This more strongly types the ubiquitous message id type by no longer
making it an integer. It keeps the actual ID opaque. Only for the
generic job API the number keeps being used. Some locations also need
to create it from an integer and call MsgId::new().
contact-requests of non-blocked senders are shown in the chatlist,
so that the user gets aware of them without opening the contact-request-chat.
however, for that, the contact-request virtual-chat-id
must be added to the beginning of the list,
otherwise it won't get noticed by the user.
Function `query_row` executes query and calls callback function to process
row returned. Function query_row_col() is special case, that provides
callback function, which returns value of one particular column of row,
ignoring others.
In all cases, that particular column was 0 (first and only column of
query result), since there is no point to select more than one column
with this function -- they are discarded anyway.
This commit removes that redundancy, removing column number argument of
query_row_col() function and adjusting call sites accordingly.
* refactor(contact): rename and rusty memory allocations
* refactor(contact): use enum to indidcate origin
* refactor(contact): safe blocking and unblocking api
* refactor(contact): only safe and no more cstrings
Add a trait for str.strdup() to replace to_cstring() which avoid the
signature ambiguity with .to_string().
Also instruduce CString::yolo() as a shortcut to
CString::new().unwrap() and use it whenever the variable does can be
deallocated by going out of scope. This is less error prone.
Use some Path.to_c_string() functions where possible.
