[Feature] Add option to add/edit/delete categories from categories dropdown

[arielj]

Fixes #3415
Fixes #3406

This PR adds a new dialog to add/edit/delete categories without having to right click a game card.

manage-categories.mp4

Some notes:

• I ordered the categories alphabetically for now, at some point we can let users reorder them but currently it the order changes when editing which is not good
• The video was recorded before the last changes so some issue that can be seen in the videos are fixed

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Use the following Checklist if you have changed something on the Backend or Frontend:

• Tested the feature and it's working on a current and clean install.
• Tested the main App features and they are still working on a current and clean install. (Login, Install, Play, Uninstall, Move games, etc.)
• Created / Updated Tests (If necessary)
• Created / Updated documentation (If necessary)

[flavioislima]

Codewise and feature-wise looks good.
But this design I think doesn't work:

I think both buttons should be at the same place: bottom.
try something like:
Select ALL
Manage Categories.

I think that would look better.

[arielj]

Codewise and feature-wise looks good. But this design I think doesn't work:

I think both buttons should be at the same place: bottom. try something like: Select ALL Manage Categories.

I think that would look better.

just pushed this change

[flavioislima]

Tested here and looks good, will merge to add to the next release.

One minor improvement for the future though: When clicking on Select All it also selects the 'Uncategorized' this has the same effect as selecting none.

[flavioislima]

LGTM