[Feature][SDK] Transform supports padding of left and right strings

[Zkplo]

Description

• parent issue [Umbrella] Tencent Rhino-bird: Expand InLong Transform functions #10796

RPAD(s1,len,s2)：Fill string s2 at the end of string s1 to make the length of the string len
LPAD(s1,len,s2)：Fill string s2 at the beginning of string s1 to make the string length len

Use case

RPAD('12',5,'34') -> "12343"
RPAD('1234',2,'5') -> "12"
RPAD('1',5,'') -> ""
RPAD(null,2,'34') or RPAD('12',null,'34') or RPAD('12',2,null) or RPAD('12',-1,'34') -> null

LPAD('12',5,'34') -> "34312"
LPAD('1234',2,'5') -> "12"
LPAD('1',5,'') -> ""
LPAD(null,2,'34') or LPAD('12',null,'34') or LPAD('12',2,null) or LPAD('12',-1,'34') -> null

Are you willing to submit PR?

• Yes, I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct