More notification metrics fixes (#26889)

* Explicitly have the client tell the server when it should expect an ACK

* Don't count missing profile errors for your own posts, added comment

* Fix test

* Make postedAck a parameter in WebSocketClient

* Snapshot fixes

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Co-authored-by: Mattermost Build <build@mattermost.com>

webapp/channels/src/components/post_view/post_body_additional_content/__snapshots__/post_body_additional_content.test.tsx.snap

@@ -111,6 +111,7 @@ exports[`PostBodyAdditionalContent with a normal link Should render the plugin c
         "messageListeners": Set {},
         "missedEventCallback": null,
         "missedMessageListeners": Set {},
+        "postedAck": false,
         "reconnectCallback": null,
         "reconnectListeners": Set {},
         "responseCallbacks": Object {},
@@ -157,6 +158,7 @@ exports[`PostBodyAdditionalContent with a normal link Should render the plugin c
         "messageListeners": Set {},
         "missedEventCallback": null,
         "missedMessageListeners": Set {},
+        "postedAck": false,
         "reconnectCallback": null,
         "reconnectListeners": Set {},
         "responseCallbacks": Object {},