Add `make source_archive_complete` target

Add a `source_archive_complete` target for `make` that creates a source
archive including the source packages of Blender's dependencies.

This expands `make_source_archive.py` to include files from
`${BUILD_DIR}/source_archive/packages/` as well.

Reviewed By: dfelinto

Maniphest Tasks: T86124

Differential Revision: https://developer.blender.org/D10727

Action preview rendering: properly tag the object when done

Rendering a preview for an Action requires temporarily modifying the pose
of some object (otherwise there is nothing to render); after this is done,
the object needs to be tagged correctly to flush the temporary changes.

Pose Library: lock the interface while flipping a pose

Flipping a pose Action temporarily changes the pose itself, which can cause
visual jitter. This is prevented by locking the interface while flipping.

Cleanup: Asset Browser, move Action-specific rendering code

Move some Action-specific code required to render the preview image into
the part of the code that is already Action-specific.

No functional changes.

Merge remote-tracking branch 'origin/master' into asset-browser-poselib

Cleanup: preview rendering, push bContext a bit further down the call stack

Pass `bContext *C` a bit further down the call stack, to prevent
exploding the number of parameters of `ED_preview_icon_render()`. An
upcoming change will require access to yet another context member, and
this can now be done without adding yet another parameter.

No functional changes.

Merge remote-tracking branch 'origin/master' into asset-browser-poselib

Asset Browser: Apply a pose before rendering its preview icon

When rendering the preview icon of an Action, apply it to the pose
object first. This ensures that the "Refresh" button of a pose actually
uses that pose.

This splits some functions into two flavours, one that acts on all bones
and one that acts on the selected bones only. Normal use of the pose
library only acts on selected bones, but for the preview the entire pose
from the library is applied, regardless of selection.

Previews: allow undo'ing datablock preview generation

Allow users to undo the effect of the "Generate Preview" operator in the
asset browser (`ED_OT_lib_id_generate_preview`). Without this, the
button is too dangerous.

Cleanup: Pose library, move pose backup code into its own file

Move the pose backup & restore functionality into its own file, so that
the functions can be called from other places in Blender as well.

No functional changes.