feat: key-contacts

This change introduces a new type of contacts
identified by their public key fingerprint
rather than an e-mail address.

Encrypted chats now stay encrypted
and unencrypted chats stay unencrypted.
For example, 1:1 chats with key-contacts
are encrypted and 1:1 chats with address-contacts
are unencrypted.
Groups that have a group ID are encrypted
and can only contain key-contacts
while groups that don't have a group ID ("adhoc groups")
are unencrypted and can only contain address-contacts.

JSON-RPC API `reset_contact_encryption` is removed.
Python API `Contact.reset_encryption` is removed.
"Group tracking plugin" in legacy Python API was removed because it
relied on parsing email addresses from system messages with regexps.

Co-authored-by: Hocuri <hocuri@gmx.de>
Co-authored-by: iequidoo <dgreshilov@gmail.com>
Co-authored-by: B. Petersen <r10s@b44t.com>

test-data/golden/receive_imf_older_message_from_2nd_device

@@ -1,4 +1,4 @@
-Single#Chat#10: bob@example.net [bob@example.net] 
+Single#Chat#10: bob@example.net [bob@example.net] Icon: 4138c52e5bc1c576cda7dd44d088c07.png 
 --------------------------------------------------------------------------------
 Msg#10: Me (Contact#Contact#Self): We share this account  √
 Msg#11: Me (Contact#Contact#Self): I'm Alice too  √

test-data/golden/test_old_message_1

@@ -1,4 +1,4 @@
-Single#Chat#10: Bob [bob@example.net] 
+Single#Chat#10: Bob [PGP bob@example.net] 
 --------------------------------------------------------------------------------
 Msg#10: info (Contact#Contact#Info): Messages are guaranteed to be end-to-end encrypted from now on. [NOTICED][INFO 🛡️]
 Msg#11: info (Contact#Contact#Info): Bob sent a message from another device. [NOTICED][INFO 🛡️❌]

test-data/golden/test_old_message_2

@@ -1,4 +1,4 @@
-Single#Chat#10: Bob [bob@example.net] 
+Single#Chat#10: Bob [PGP bob@example.net] 
 --------------------------------------------------------------------------------
 Msg#10: info (Contact#Contact#Info): Messages are guaranteed to be end-to-end encrypted from now on. [NOTICED][INFO 🛡️]
 Msg#11: info (Contact#Contact#Info): Bob sent a message from another device. [NOTICED][INFO 🛡️❌]

test-data/golden/test_old_message_3

@@ -1,4 +1,4 @@
-Single#Chat#10: Bob [bob@example.net] 🛡️
+Single#Chat#10: Bob [PGP bob@example.net] 🛡️
 --------------------------------------------------------------------------------
 Msg#10: info (Contact#Contact#Info): Messages are guaranteed to be end-to-end encrypted from now on. [NOTICED][INFO 🛡️]
 Msg#11🔒:  (Contact#Contact#10): Heyho from my verified device! [FRESH]

test-data/golden/test_old_message_5

@@ -1,4 +1,4 @@
-Single#Chat#10: Bob [bob@example.net] 
+Single#Chat#10: Bob [bob@example.net] Icon: 4138c52e5bc1c576cda7dd44d088c07.png 
 --------------------------------------------------------------------------------
 Msg#10: Me (Contact#Contact#Self): Happy birthday, Bob!  √
 Msg#11:  (Contact#Contact#10): Happy birthday to me, Alice! [FRESH]

test-data/golden/test_outgoing_encrypted_msg

@@ -0,0 +1,5 @@
+Single#Chat#10: bob@example.net [KEY bob@example.net] 🛡️
+--------------------------------------------------------------------------------
+Msg#10: info (Contact#Contact#Info): Messages are guaranteed to be end-to-end encrypted from now on. [NOTICED][INFO 🛡️]
+Msg#11🔒: Me (Contact#Contact#Self): Test – This is encrypted, signed, and has an Autocrypt Header without prefer-encrypt=mutual.  √
+--------------------------------------------------------------------------------

test-data/golden/test_outgoing_mua_msg

@@ -1,7 +1,4 @@
-Single#Chat#10: bob@example.net [bob@example.net] 🛡️
+Single#Chat#11: bob@example.net [bob@example.net] Icon: 4138c52e5bc1c576cda7dd44d088c07.png 
 --------------------------------------------------------------------------------
-Msg#10: info (Contact#Contact#Info): Messages are guaranteed to be end-to-end encrypted from now on. [NOTICED][INFO 🛡️]
-Msg#11🔒:  (Contact#Contact#10): Heyho from DC [FRESH]
 Msg#12: Me (Contact#Contact#Self): One classical MUA message  √
-Msg#13🔒: Me (Contact#Contact#Self): Sending with DC again  √
 --------------------------------------------------------------------------------

test-data/golden/test_outgoing_mua_msg_pgp

@@ -0,0 +1,6 @@
+Single#Chat#10: bob@example.net [KEY bob@example.net] 🛡️
+--------------------------------------------------------------------------------
+Msg#10: info (Contact#Contact#Info): Messages are guaranteed to be end-to-end encrypted from now on. [NOTICED][INFO 🛡️]
+Msg#11🔒:  (Contact#Contact#10): Heyho from DC [FRESH]
+Msg#13🔒: Me (Contact#Contact#Self): Sending with DC again  √
+--------------------------------------------------------------------------------

test-data/golden/test_verified_oneonone_chat_enable_disable

@@ -1,4 +1,4 @@
-Single#Chat#10: Bob [bob@example.net] 🛡️
+Single#Chat#10: Bob [PGP bob@example.net] 🛡️
 --------------------------------------------------------------------------------
 Msg#10: info (Contact#Contact#Info): Messages are guaranteed to be end-to-end encrypted from now on. [NOTICED][INFO 🛡️]
 Msg#11: info (Contact#Contact#Info): Bob sent a message from another device. [NOTICED][INFO 🛡️❌]

test-data/golden/verified_chats_message_from_old_dc_setup

@@ -1,8 +0,0 @@
-Single#Chat#10: bob@example.net [bob@example.net] 🛡️
---------------------------------------------------------------------------------
-Msg#10: info (Contact#Contact#Info): Messages are guaranteed to be end-to-end encrypted from now on. [NOTICED][INFO 🛡️]
-Msg#11🔒:  (Contact#Contact#10): Now i have it! [FRESH]
-Msg#12: info (Contact#Contact#Info): bob@example.net sent a message from another device. [NOTICED][INFO 🛡️❌]
-Msg#13:  (Contact#Contact#10): Soon i'll have a new device [FRESH]
-Msg#14: info (Contact#Contact#Info): Messages are guaranteed to be end-to-end encrypted from now on. [NOTICED][INFO 🛡️]
---------------------------------------------------------------------------------