Arsenal - Fill left panel over multiple frames

[LinkIsGrim]

When merged this pull request will:

• Title.
• Cache missionConfigFile insignias.

See #9787 first.

The intent is to reduce/eliminate the noticeable hangups when switching tabs or opening the arsenal with lots of items. CUP + CFP + WS already puts the weapons count at around ~1000 with a full arsenal.

Specifics:

• Up to 250 items are processed per frame.
• If less than 250 items are available, filling is done in a single frame.
• The arsenal center's current item (if equipped) for that tab is added and selected first so actions, stats, and the right panel can be handled immediately for responsiveness.
• The button for the current tab is disabled until all items are added.
• If the player switches tabs before all items are added, filling for the previous tab is aborted.
• The leftPanelFilled event is only raised once all virtual items for that tab are processed. Anything using API shouldn't be affected.
• Sorting is only done after all items are processed.

Known issues:

• Opening and closing the loadouts display before processing is done will overload the tab.
• Since the current item is added first, the scroll bar will jump around noticeably if the item is sorted lower on the panel:

ArmA.3_2024.02.09-08.06.mp4

IMPORTANT

• If the contribution affects the documentation, please include your changes in this pull request so the documentation will appear on the website.
• Development Guidelines are read, understood and applied.
• Title of this PR uses our standard template Component - Add|Fix|Improve|Change|Make|Remove {changes}.