IR Light - Fix bad item replacements and switching to primary weapons

[johnb432]

When merged this pull request will:

• Title: Implementation seemed to only account for primary weapon usage, despite the IR lights being compatible with launchers such as the MAAWS and the Titan.
• Removes 2 unused functions.
• Requires Common - Add ace_common_fnc_switchAttachmentMode #10135.
• Requires Common - Improve persistent lights/lasers #10118 to restore previous laser status, as I feel like it should handle that (and not this component).
• Added a weapon parameter to switchAttachmentMode (for last bullet point)
• Made switchPersistentLaser take pointer switching into account (should have been added in Common - Improve persistent lights/lasers #10118, but overlooked)
• Fixed IR light attachments being added to the wrong weapon (was previously being added to currentWeapon, when it wasn't necessarily the unit's current weapon)

Question I have:
There are now 2 unused functions. Can we remove them?

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• Title of this PR uses our standard template Component - Add|Fix|Improve|Change|Make|Remove {changes}.

[johnb432]

• Added a weapon parameter to switchAttachmentMode (for 3rd bullet point)
• Made switchPersistentLaser take pointer switching into account
• Fixed IR light attachments being added to the wrong weapon (was previously being added to currentWeapon, when it wasn't necessarily the unit's current weapon)