Ensure usable and consistent behavior of history when using multiple tabs simultaneously

[Inwerpsel]

Currently interacting with the editor in multiple browser tabs at the same time very likely results in a mangled history, so it's better not to do it.

It's probably fine if the second tab is just open without any editor actions (that are recorded), but any actions that are done will overwrite actions done in the first tab after the second one was opened.

What can be done?

• Lock all other tabs upon interaction, and sync when unlocking
• Automatically sync at all times (except for a few interactions like inspection, which would require changes to how inspection is handled)
• Store more history per session, rather than globally