Optimize `lower()/upper()` string function with ASCII fast path

[2010YOUY01]

Is your feature request related to a problem or challenge?

Part of #12306

#12306 has introduced the rationale for ASCII fast path in detail

This optimization has already been implemented on char_length() string function and got some performance improvement
(In PR #12356)

Describe the solution you'd like

Implement ASCII fast path for lower() and upper() function

Describe alternatives you've considered

No response

Additional context

No response

[tshauck]

take

[thinh2]

Hi @tshauck, are you working on this issue?

[tshauck]

@thinh2 Sorry to leave you hanging. I got started but got busy. If you want to work on it, by all means.

[thinh2]

thanks @tshauck . Let me try to do it.

[Omega359]

Note that lower/upper likely already does this. See

datafusion/datafusion/functions/src/string/common.rs

Line 377 in f190fc6

if value_data.is_ascii() {

and

datafusion/datafusion/functions/src/string/common.rs

Line 400 in f190fc6

fn case_conversion_ascii_array<'a, O, F>(