[API] raise libSRT version number to 1.5.5

Fix SIGABRT when bonding option is too long (#3210)

* Fix SIGABRT when bonding option is too long

* Move the UT to test_bonding.cpp

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Co-authored-by: Clément Gérouville <[email protected]>

[core] Fixed group import option.

SRTO_CONNTIMEO, SRTO_PAYLOADSIZE, SRTO_PBKEYLEN had size autodetection bugs.

[core] Fixed static variable usage in the crypto module (#3047).

Static variable `hcrypt_MsgInfo _hcMsg_SRT_MsgInfo` was declared twice.
There was a mutual dependency between `_hcMsg_SRT_MsgInfo` and `hcryptMsg_SRT_ParseMsg(..)`.

[core] Fixed nonchecked empty config for packetfilter (#3031).

[apps] Fixed compiler warnings (G++ 9.4)

[docs] Fixed API doc: SRT_INVALID_SOCK instead of SRT_ERROR in str_ac…

…cept (#2785).

The functions srt_accept() and srt_accept_bond() return a SRTSOCKET.
In case of error, the returned value is SRT_INVALID_SOCK, not SRT_ERROR.
In practice, the two values are identical (-1) but they do not have
the same semantics.

[apps] Fixed conditional IP_ADD_SOURCE_MEMBERSHIP in testmedia (#2780).

[docs] Minor updates to AEAD docs plus changed v1.6.0 to 1.5.2 in som…

…e files

[core] Correct remaining endianness issues

Fixes the last two remaining test failures on big-endian.  These
operations were all already no-ops on little-endian, and unnecessarily
byteswapped the IP addresses on big-endian.

Closes: #2697