Construct event channel outside of Context

This allows account manager to construct a single event channel and
inject it into all created contexts instead of aggregating events from
separate event emitters.

benches/contacts.rs

@@ -2,13 +2,16 @@ use async_std::task::block_on;
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
 use deltachat::contact::Contact;
 use deltachat::context::Context;
+use deltachat::Events;
 use tempfile::tempdir;
 
 async fn address_book_benchmark(n: u32, read_count: u32) {
     let dir = tempdir().unwrap();
     let dbfile = dir.path().join("db.sqlite");
     let id = 100;
-    let context = Context::new(dbfile.into(), id).await.unwrap();
+    let context = Context::new(dbfile.into(), id, Events::new())
+        .await
+        .unwrap();
 
     let book = (0..n)
         .map(|i| format!("Name {}\naddr{}@example.org\n", i, i))

benches/get_chat_msgs.rs

@@ -6,10 +6,13 @@ use criterion::{black_box, criterion_group, criterion_main, Criterion};
 use deltachat::chat::{self, ChatId};
 use deltachat::chatlist::Chatlist;
 use deltachat::context::Context;
+use deltachat::Events;
 
 async fn get_chat_msgs_benchmark(dbfile: &Path, chats: &[ChatId]) {
     let id = 100;
-    let context = Context::new(dbfile.into(), id).await.unwrap();
+    let context = Context::new(dbfile.into(), id, Events::new())
+        .await
+        .unwrap();
 
     for c in chats.iter().take(10) {
         black_box(chat::get_chat_msgs(&context, *c, 0).await.ok());
@@ -21,7 +24,9 @@ fn criterion_benchmark(c: &mut Criterion) {
     // messages, such as your primary account.
     if let Ok(path) = std::env::var("DELTACHAT_BENCHMARK_DATABASE") {
         let chats: Vec<_> = async_std::task::block_on(async {
-            let context = Context::new((&path).into(), 100).await.unwrap();
+            let context = Context::new((&path).into(), 100, Events::new())
+                .await
+                .unwrap();
             let chatlist = Chatlist::try_load(&context, 0, None, None).await.unwrap();
             let len = chatlist.len();
             (0..len).map(|i| chatlist.get_chat_id(i).unwrap()).collect()

benches/get_chatlist.rs

@@ -3,6 +3,7 @@ use criterion::{black_box, criterion_group, criterion_main, Criterion};
 
 use deltachat::chatlist::Chatlist;
 use deltachat::context::Context;
+use deltachat::Events;
 
 async fn get_chat_list_benchmark(context: &Context) {
     Chatlist::try_load(context, 0, None, None).await.unwrap();
@@ -12,8 +13,9 @@ fn criterion_benchmark(c: &mut Criterion) {
     // To enable this benchmark, set `DELTACHAT_BENCHMARK_DATABASE` to some large database with many
     // messages, such as your primary account.
     if let Ok(path) = std::env::var("DELTACHAT_BENCHMARK_DATABASE") {
-        let context =
-            async_std::task::block_on(async { Context::new(path.into(), 100).await.unwrap() });
+        let context = async_std::task::block_on(async {
+            Context::new(path.into(), 100, Events::new()).await.unwrap()
+        });
         c.bench_function("chatlist:try_load (Get Chatlist)", |b| {
             b.to_async(AsyncStdExecutor)
                 .iter(|| get_chat_list_benchmark(black_box(&context)))

benches/receive_emails.rs

@@ -8,6 +8,7 @@ use deltachat::{
     context::Context,
     dc_receive_imf::dc_receive_imf,
     imex::{imex, ImexMode},
+    Events,
 };
 use tempfile::tempdir;
 
@@ -42,7 +43,9 @@ async fn create_context() -> Context {
     let dir = tempdir().unwrap();
     let dbfile = dir.path().join("db.sqlite");
     let id = 100;
-    let context = Context::new(dbfile.into(), id).await.unwrap();
+    let context = Context::new(dbfile.into(), id, Events::new())
+        .await
+        .unwrap();
 
     let backup: PathBuf = std::env::current_dir()
         .unwrap()

benches/search_msgs.rs

@@ -1,12 +1,15 @@
 use async_std::task::block_on;
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
 use deltachat::context::Context;
+use deltachat::Events;
 use std::path::Path;
 
 async fn search_benchmark(path: impl AsRef<Path>) {
     let dbfile = path.as_ref();
     let id = 100;
-    let context = Context::new(dbfile.into(), id).await.unwrap();
+    let context = Context::new(dbfile.into(), id, Events::new())
+        .await
+        .unwrap();
 
     for _ in 0..10u32 {
         context.search_msgs(None, "hello").await.unwrap();