feat: implement mute conversation support for Mastodon

This feature allows users to visually hide muted conversations from the Home timeline. It includes:

- Automatic filtering of muted posts in Home.

- Immediate visual removal of posts when muting a conversation.

- New 'mute_conversation' action in context menu and keyboard shortcuts.

- Default shortcut: Alt+Win+Shift+Delete

- Win10/11 shortcut: Ctrl+Alt+Win+Backspace

src/keystrokeEditor/actions/mastodon.py

@@ -54,4 +54,5 @@ actions = {
     "update_buffer": _(u"Updates the buffer and retrieves possible lost items there."),
     "ocr_image": _(u"Extracts the text from a picture and displays the result in a dialog."),
     "add_alias": _("Adds an alias to an user"),
+    "mute_conversation": _("Mute/Unmute conversation"),
 }