Reconsider naming of `libar-*.so.1` libraries

[slyon]

The "ar" in "libar-*" stands for "AudioReach", but can be easily confused with binutils' ar archive format. We might consider spelling it out as libaudioreach-*.so.1

Reported upstream: AudioReach/audioreach-graphservices#110

[slyon]

Upstream is moving into that direction, via:

• build: rename shared libraries to libaudioreach AudioReach/audioreach-graphservices#116
• pal: replace hardcoded lib flags with PKG_CHECK_MODULES AudioReach/audioreach-pal#87
• agm: replace hardcoded lib flags with PKG_CHECK_MODULES AudioReach/audioreach-graphmgr#138