Migrate `IMuonRawBuffer` and `MuonRawBuffer` from LHCb to here

Initial steps towards LHCb#338 (moved)

• migrate IMuonRawBuffer and MuonRawBuffer from LHCb into MuonTrackRec which is the sole component package using it
• strip some unused functionality from MuonRawBuffer, eg. the needless inheritance from the deprecated Decoder::ToolBase

note: this also migrates the history of IMuonRawBuffer and MuonRawBuffer hence the number of commits (unfortunately the history doesn't recognize renaming of files, so it doesn't go all the way, but given that this code is probably not useful for run3 that probably doesn't matter)