HaikuDepot : Refactor Screenshots

Rework the way in which the application deals
with screenshots so that there is a repository
of screenshots that is referenced from
identifiers on the package model and not that
the screenshot bitmaps are stored with the
model and not cleaned up.

Change-Id: I632def96852a518b3f6b1c8b81909de117bbbc54
Reviewed-on: https://review.haiku-os.org/c/haiku/+/7296
Reviewed-by: Andrew Lindesay <apl@lindesay.co.nz>

HaikuDepot: Log Process Report

To make it easier to understand what process
elements are taking a long time to run, a
small simple report is output as debug log
at completion of a process.

Change-Id: I09b93c494961e7abbbd22a3c58c64631f08025af
Reviewed-on: https://review.haiku-os.org/c/haiku/+/7075
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>

HaikuDepot: Remove Custom List

Closes #15534

Change-Id: I23fa60145607c3e8f25552f24c5e2c630b940537
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3758
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

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>

use .IsSet() instead if .Get() != NULL

Change-Id: Ia2b7a719fd398e78cc3b11d4f7b02cb81179f65f
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3488
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>

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>

HaikuDepot: Custom List Removal (Depots)

Remove use of custom list class where it is not
really required in the area of Depots. Also
convert the use of Depots to be wrapped in
BReference to match other model objects. At the
same time some data-loading logic has been
simplified.

Relates To #15534

Change-Id: Ie6fcc35f258a0c69c44990e4b09f6c32ec79945d
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3225
Reviewed-by: Rene Gollent <rene@gollent.com>

HaikuDepot: Icon / Tarball Handling

Instead of exploding the tar-ball of icons from
HDS, keep it as a tar-ball, index it and read
data directly out from specific indicies on demand.

This will speed up the process of downloading
the icons by removing the unpack. Also updates
will be faster by avoiding the need to delete the
old icon files.

Because icons are loaded on-demand, the start
time is faster by avoiding all the icon loads.
There are also savings on memory consumption.

Indexing on each load is surprisingly fast so
no external index is maintained. Likewise for
the tar-balls's meta-data.

This commit does not cover the implementation
of an LRU cache of the icons in memory.

Relates to #15370

Change-Id: Ia1647d8c805be89618f493d2592bf7877fca3f14
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3205
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>