fixed spec because of object key change

auto open new folder when creating item
scroll dropdown into view when opening

Closes #44838

added arrow key navigation in the dropdown
enter & click open the file
highlight occurrences of the searched text in the drppdown item
fixed some performance issues when rendering
limit the dropdown items to a maximum of 20 - this may change to more
depending on other performance changes

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.

blur the collapse button on click

after a commit the files are correctly reset
correctly enables the ability to have different staged & unstaged changes in the same file

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/4541

this reduces the amount of duplicated code between creating a temp tree & a temp file. We just pass a type that dispatches some extra actions for files

this now all goes through the 1 mutationn & the web worker. This keeps all the logic the same for multiple directions

it wasn't previously affecting the performance in any way, however this keeps all the logic of creating folders & files in the worker which we can just post to whenever we need to

[ci skip]

[ci skip]

[ci skip]

Closes #4568

Signed-off-by: Rémy Coutable <remy@rymai.me>

Signed-off-by: Rémy Coutable <remy@rymai.me>

Signed-off-by: Rémy Coutable <remy@rymai.me>

added more specs