fix quick replies from notifications (#4250)

While working on #4249 I noticed that quick replies also don't work as
expected. The notification just stays in the sending state forever.
There are actually 2 problems:
- Notifications are sent in `NotificationFetcher` with the id of the
Mastodon notification as tag and the current account id as id. The wrong
notification id was forwarded to `SendStatusBroadcastReceiver` so it
never had a chance of updating the notification.
- Notifications containing an active remote input can't be cancelled
(they just stop their animation when doing so). So instead I update the
notification with info that the reply is being sent and have it dismiss
automatically.

I also tried replacing the original notification with the "sending"
notification of `SendStatusService`, but that doesn't work because
`Service.startForeground` doesn't have a tag parameter, only an id.

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Co-authored-by: Willow <charlag@tuta.io>

app/src/main/res/values/strings.xml

@@ -227,8 +227,8 @@
     <string name="confirmation_domain_unmuted">%s unhidden</string>
     <string name="confirmation_hashtag_unfollowed">#%s unfollowed</string>
 
-    <string name="post_sent">Sent!</string>
-    <string name="post_sent_long">Reply sent successfully.</string>
+    <string name="reply_sending">Sending…</string>
+    <string name="reply_sending_long">Your reply is being sent.</string>
 
     <string name="hint_domain">Which instance?</string>
     <string name="hint_compose">What\'s happening?</string>