multimedia/libde265: Update to 1.0.8

• Use upstream release archive as recommended by Porters Handbook (see USE_GITHUB section)
• Backport upstream commits 900772c3e9ee1e106b93283fd8e7633d52899e40 , 7d5aeb5f11531de33f5b7ae0e768ffc50da4facb , dbff9077462899fc8e3b39907d43c2a6ad54e9f3 , a3f1c6a0dea2b0d4a531255ad06ed40cdb184d25 and 4c0fe2c149c68ece57fde4cb11e05b5fb572da4b for various bug fixes
• Package dec265 utility, also rename it as libde265-dec265 to match Debian's repository
• Import patches from Debian to only expose public API and disable tools that don't build without internal API exposed.

References:

https://github.com/strukturag/libde265/commit/900772c3e9ee1e106b93283fd8e7633d52899e40
https://github.com/strukturag/libde265/commit/7d5aeb5f11531de33f5b7ae0e768ffc50da4facb
https://github.com/strukturag/libde265/commit/dbff9077462899fc8e3b39907d43c2a6ad54e9f3
https://github.com/strukturag/libde265/commit/a3f1c6a0dea2b0d4a531255ad06ed40cdb184d25
https://github.com/strukturag/libde265/commit/4c0fe2c149c68ece57fde4cb11e05b5fb572da4b
https://salsa.debian.org/multimedia-team/libde265/-/blob/master/debian/patches/only_export_decoder_api.patch
https://salsa.debian.org/multimedia-team/libde265/-/blob/master/debian/patches/disable_tools.patch

Patch initially submitted by vishwin

PR: 251442
Reported by: vishwin
Approved by: kwm (maintainer timeout, 14+ months)