This commit adds a tab for assignments in the experimental user menu. The assignments tab behaves very similarly to the bookmarks and messages tab in core: it displays the user's unread assign notifications first and then fills the rest of available space in the menu with assignments (same content that the current user menu displays).
More details of the experimental user menu can be found in https://github.com/discourse/discourse/pull/17379.
c396605d2f introduces a call to the `TopicView.on_preload` method which was added in discourse 2.8.0.beta2.
This commit pins the plugin to the commit before the one linked above for Discourse instances running version 2.8.0.beta1 or older
Jarek Radosz
David Taylor
Osama Sayegh
Jeff Wong
Alan Guo Xiang Tan
Andrei Prigorshnev
Vinoth Kannan