multimedia/gstreamer1: Update to 1.24.8

Mk/Uses/gstreamer.mk:
- Sort, fix whitespace issues and typos
- Promote several common variables to improve maintainer QOL
*   There's now no need to set manually set PORTVERSION nor
    SOVERSION in several Makefiles
*   This will help to prevent not updating some components
*   A note has been added, however, to remind maintainers
    to remake distinfo for certain ports
- Improve documentation

multimedia/gstreamer1-plugins-webrtc:
- New port split from multimedia/gstreamer1-plugins-bad
- multimedia/gstreamer1-plugins-rust has been updated

Update gstreamer1 to upstream release 1.20.3

PR:		261585
Reviewed by:	riggs,jbeich,tcberner

Differential Revision:	https://reviews.freebsd.org/D36850

textproc/libxml2: bump all LIB_DEPENDS consumers

This is a separate commit to facilitate easier cherry-picking for
quarterly.

PR: 262853, 262940, 262877, 263126
Approved by: fluffy (mentor)

textproc/libxml2: bump all dependencies

This should make sure that all dependent ports will pick
up the new version commited with a13ec21cd733f67a9fc0dc00ab45268bdc236246

One more small cleanup, forgotten yesterday.
Reported by:	lwhsu

Remove # $FreeBSD$ from Makefiles.

Update GStreamer to 1.14.4.

PR:		231406
Submitted by:	Greg V <greg@unrelenting.technology>
Exp-run by:	antoine
Approved by:	portmgr (antoine)

Update graphics/openjpeg to 2.3.0

Changes:	https://github.com/uclouvain/openjpeg/blob/master/CHANGELOG.md
PR:		222817
Exp-run by:	antoine

Update GStreamer 1.x suite to 1.12.3.

ChangeLog: https://gstreamer.freedesktop.org/releases/1.12/#1.12.3

Update graphics/openjpeg to 2.2.0

Changes:	https://github.com/uclouvain/openjpeg/blob/master/CHANGELOG.md
PR:		221478
Exp-run by:	antoine

Update GStreamer1 to 1.6.2.
Update GStreamer1-vaapi to 0.7.0.

* Spell GStreamer consistently. [1]
* Fix typo in py3kplist in py3-gstreamer1 [1]
* Improve plugins COMMENTS (more improvements welcome)
* Actually include the gstreamer1-libav update this time.

PR:		204204 [1] (based on)
Submitted by:	olivierd@ [1]

Update Gstreamer framework to 1.4.5.

Fix 41 gstreamer1-plugins- ports that were creating empty packages

With hat:	portmgr

Big Gstreamer update:

Update gstreamer, gstreamer-plugins, -good, -bad and -ugly ports to 1.4.4.
Update gstreamer1-plugins-gnonlin to 1.4.0.
Update py-gstreamer1 and py3-gstreamer1 to 1.4.0.

Add multimedia/gstreamer1-editing-services. GES is a high-level library
for facilitating the creation of audio/video non-linear editors.

Add pulseaudio plugin now that pulseaudio is updated and add the gl plugin.

Drop :keepla from USES=libtool.
Drop @dirrm[try] from plists and drop gnomehier from USE_GNOME
Switch to optionhelpers in multimedia/gstreamer1.

PR:		194922 (merged with my own WIP)
Submitted by:	olivierd

Update openjpeg to 2.1.0.

Version 2.x is incompatible with openjpeg 1.5. Preserve it as openjpeg15
and update users.

Approved by:	portmgr (implicit) for NO_STAGE ports

Update gstreamer 1.0 ports to version 1.2.4.

When linking a library libA with a library libB using libtool, if libB.la
exists, libtool will add all libraries libB.la refers to (dependency_libs
field) to the linker command line and store them in the dependency_libs
field of libA.la.  So everything that subsequently links with libA will also
link to these extra libraries.  This causes too much overlinking.

This commit modifies Mk/Uses/libtool.mk so it empties the dependency_libs
field in .la libraries during staging.  However, because .la libraries have
very limited use when dependency_libs is empty it makes sense to completely
remove them during staging.

So with this commit USES=libtool is modified to remove .la libraries and a
new form (USES=libtool:keepla) is introduced in case they need to be kept
(dependency_libs is still emptied).

Update to 1.2.1.

Retire celt plugin, it was removed in flavor for the opus plugin.
Add new webp, kate and openjpeg plugin.