Restore packaging of B2BUA server and internal libmbedtls

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Fix mbedtls shared lib install (for rpm packaging)

relay static/shared directives to mbedtls

this fixes package dependencies: we embed our own version of mbedtls

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Fix B2BUA flexisip testsuite

Minor refactoring

SDK: Use video direction of local parameter to create SDP if the participant is in ScheduledForJoining state. Tester: Increase wait time for video to be established and bandwidth computed

Disable event log in the bridging conference. The B2BUA doesn't need it
and it interferes with media streams

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Remove B2BUA dependency on FFMPEG and V4L

Using Mire for Trenscrypter tests

Also adds debug asserts and increases timeouts in trenscrypter tests

This is to fix B2BUA tests failing on CI because call operations take too long
(in Sanitizer build)

Co-authored-by: Andrea Gianarda <andrea.gianarda@belledonne-communications.com>
Co-authored-by: François Grisez <francois.grisez@belledonne-communications.com>
Co-authored-by: Johan Pascal <johan.pascal@belledonne-communications.com>