[connector:php] new volume options `encoding`, `locale`

for support non UTF-8 server

ref: Studio-42#443, Studio-42#446, Studio-42#466, Studio-42#570, Studio-42#601, Studio-42#701, Studio-42#911

This solution would correct these related problems. It would become possible to be to designate `encoding`, `locale` of a volume option and connect non-UTF-8 to a server.