[SQL] Support MySQL SHA1 & SHA function.

[dongzl]

What would you like to be added:

Why is this needed:

ref #454

official document:
https://dev.mysql.com/doc/refman/5.6/en/encryption-functions.html#function_sha1

code:
https://github.com/arana-db/arana/tree/master/pkg/runtime/function/scripts/crypto.js

reference code:

https://github.com/arana-db/arana/tree/master/pkg/runtime/function2/abs.go

need register twice.

func init() {
   proto.RegisterFunc("SHA", shaFunc{})
   proto.RegisterFunc("SHA1", shaFunc{})
}