Plugin store queried on main thread even if preferences are not opened
The Plugin store is loaded on the main thread, and is starting network requests from the main thread, at some places like when selecting a conversation, which creates noticeable UI freezes and glitches, for instance when selecting a conversation.
All of this while Jami didn't have any plugin installed.
- the Plugin store should not be refreshed on the main thread
- the Plugin store should not be refreshed if not needed (to be checked that the plugin store doesn't repetitively make network requests when using Jami)
- the Plugin store should not be refreshed or even loaded if no plugin is installed and the user doesn't go to the Extension settings page.