Closes #45412

Closes #45326

Closes #44305

Added comment for `key` usage

Changes the IDE sidebar min width to be 340px to make it more usable
after resizing.

Closes #44836

simplified SET_FILE_ACTIVE openFiles map
use .find in router so that it returns early instead of looping all the
values

pending tabs now get added into openfiles & just filtered correctly

fixes model being cached as undefined
fixed open files not being correctly mutated

clears any active files when opening pending tab

then opens the file in edit mode

Pending tabs are normal tabs that are opened from the right sidebar.
They are opened in diff mode and when changed to edit mode they get
closed
& the actual file gets opened.

Closes #44293