HaikuDepot: Remove Custom List

Further removal of the use of custom list class;
this time with the package lists.

Relates To #15534
Change-Id: I1f01ed9d5ddbd7754097ce0adbf505d6ba17fd2f
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3732
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

HaikuDepot: Memory Leak Fix

Change-Id: Ibd311d10009484ba834843149740c5a11f283202
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3500
Reviewed-by: Stephan Aßmus <superstippi@gmx.de>

HaikuDepot: LRU Cache for Icons

Only keep a fixed number of icons in memory at once.

Completes To #15370

Change-Id: I23e3a4fa7559894034f45afb3b536910ea037078
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3367
Reviewed-by: Rene Gollent <rene@gollent.com>