Give libbrpc a SONAME (ABI-stability)

[OdyX]

Is your feature request related to a problem?

According to Debian Policy guidelines, it's not realistic to ship a libbrpc without a versionned SONAME in /usr/lib/${ARCH}/; see https://manpages.debian.org/sid/dpkg-dev/dpkg-gensymbols.1.en.html#Good_library_management

Describe the solution you'd like

It'd be ideal for libbrpc to have ABI stability guaranteed by a SONAME which would only get bumped at major versions.

Describe alternatives you've considered

Making libbrpc a private library imposes that all consumers of libbrpc need to be statically compiled, or in tightly-coupled versions; that's not really sustainable.

[wwbmmm]

bRPC's ABI contains large amount of C++ data structures, it is too complex and frequently changed, it's hard to guarantee ABI stability.