It seems like Firefox delegated some of functionalities you mention to addons, like the following, recommended one: https://addons.mozilla.org/en-US/firefox/addon/tab-session-managerThere also seems to be a functionality for selecting all of your tab...
Do you mean https://addons.mozilla.org/en-US/firefox/addon/notes-by-firefox/ addon? It seems like it is abandoned (Last updated: 2 years ago (Sep 17, 2020))
