Simplify and align behaviour when clicking on Avatars and Names

This is the current behaviour in Element Web when clicking on a mydiad of names and avatars, depending on their placement;

- Room icon (title bar) -> View media (icon)
- Room name (title bar) -> Open settings
- Room mention -> Go to room
- User avatar -> Open user details
- User name -> Insert mention
- User mention -> Open user details

My specific gripe is between clicking a user's name vs clicking their avatar, this trips up first-time users.

#### Suggested solution

Add in a "quick menu" similar to discord and slack when left-clicking a user's name, avatar, and mention. Do this consistently across those three user "links". Add a context menu with a right-click that allows more things like mentioning, DM-ing, and other things.

For rooms, make clicking the room avatar and the room name (in the title) open the sidebar detail menu (so going to settings can be done from there), this adds consistency to the UI.

(Room Avatars can be viewed from the sidebar detail, when clicking directly on the avatar itself)