regex_match does not compile using the g flag

[tobyhede]

Describe the bug
The regexp_match function fails to compile when supplied a g flag.

To Reproduce
At the moment many functions including regex match are not working correctly when accessed directly via the dataframe interface (I am working on a fix for this).
To reproduce this bug, setup a test in functions.rs

    test_function!(
            RegexpMatch,
            &[
                lit(ScalarValue::Utf8(Some("abc".to_string()))),
                lit(ScalarValue::Utf8(Some("a..".to_string()))),
                lit(ScalarValue::Utf8(Some("g".to_string()))),
            ],
            Ok(Some("abc")),
            &str,
            Utf8,
            StringArray
        );

This will fail with a compile error from the regex subsystem.

Expected behavior
The regex_match function should accept "g" as the standard regex global expression flag.

Additional context
the regex_match function, that does behave as expected includes some lines to format flags into a rust pattern:
https://github.com/apache/arrow-datafusion/blob/50a98805cdd6d5383f0c124d449ed549ca13428a/datafusion/src/physical_plan/regex_expressions.rs#L139

This mapping is not present in the regex_match function.

[Jefffrey]

If we are using PostgreSQL as baseline, then supplying g flag to regexp_match() should indeed result in an error.

psql (15.1 (Debian 15.1-1.pgdg110+1))
Type "help" for help.

postgres=# select regexp_match('a', '[a-z]', 'g');
ERROR:  regexp_match() does not support the "global" option
HINT:  Use the regexp_matches function instead.
postgres=#

Reference: https://www.postgresql.org/docs/current/functions-matching.html#FUNCTIONS-POSIX-REGEXP

Supported flags: https://www.postgresql.org/docs/current/functions-matching.html#POSIX-EMBEDDED-OPTIONS-TABLE

Seems its regexp_matches() which is the one supporting g flag, but doesn't seem to be implemented in Datafusion yet (could raise an issue for this?)

Edit: created PR #4203 to improve the error message (to be like what PostgreSQL spits out)