[4.0] Rename some module helper classes

[SharkyKZ]

Summary of Changes

Renames mod_latest and mod_banners helper classes to follow the same naming conventions as in other modules.

Testing Instructions

Test that administrator's Articles - Latest and site's Banners modules still work.

Documentation Changes Required

IDK.

[chmst]

I have tested this item ✅ successfully on ec747eb

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[drmenzelit]

I have tested this item ✅ successfully on ec747eb

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[alikon]

RTC

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