v1.2.0

1. Add rb_runoptimize(), to shrink binary size of bitmaps when called(#62 by @notoriousR-O-B and @smmathews-cision-us)
2. Keep rb_exsit definition for backward compatible with verion less than 1.0(#63 by @harry-leq)
3. Add postgres19 compatibility (#67 by @sibowu-aws)
4. Validate untrusted bitmaps in the recv functions(#68 by @piki)