…ing input values

- LPAD([string] basetext, [number] x, [optional string] padtext)
- RPAD([string] basetext, [number] x, [optional string] padtext)

lpad - Prepends padtext to basetext in a way that allows as many characters as possible from padtext given an output string length of x. When x is less than or equal to the length of basetext, only characters from basetext are printed in the output. If padtext is omitted then spaces are prepended.

rpad - Appends padtext to basetext in a way that allows as many characters as possible from padtext given an output string length of x. When x is less than or equal to the length of basetext, only characters from basetext are printed in the output. If padtext is omitted then spaces are appended.

Closes apache#10173 from jpedroantunes/feature/lpad-rpad-functions and squashes the following commits:

4efc0fe <João Pedro> Add utf8_length method that ignore invalid char considering size 1
33a5a14 <João Pedro> Fix identation on function string registry
4c4b2f4 <João Pedro> Change lpad and rpad functions signature and definition
26b90b0 <João Pedro> Correct ci lint errors on gandiva
66594a0 <João Pedro> Correct lint local errors on gandiva
b6b63e9 <João Pedro> Add projector test for RPAD string function
dc72148 <João Pedro> Add function registry for RPAD string function without pad text
c270fb1 <João Pedro> Add base implementation and tests for RPAD functions
08d2053 <João Pedro> Add function registry for LPAD string function without pad text
585cad3 <João Pedro> Add base implementation and tests for LPAD function without pad texts considering string input values
73927fc <João Pedro> Add projector test for LPAD string function
2c929a9 <João Pedro> Add function registry for LPAD string function
aecaff6 <João Pedro> Add base implementation and tests for LPAD function considering string input values

Authored-by: João Pedro <[email protected]>
Signed-off-by: Praveen <[email protected]>