Type coercion for binary operators forces UTF8View to Utf8

[Omega359]

Describe the bug

This is a cleanup ticket for #12212 which had introduced logic for regexp forcing coercion to Utf8 if any side had utf8View. This looks to have been done before #12180 landed which to my understanding should negate the need for this.

However, I think fixing regexp_match to support utf8View should likely land before the special handling code and tests introduced in #12212 is removed.

To Reproduce

See

• datafusion/datafusion/expr-common/src/type_coercion/binary.rs

  Line 1109 in 7ebd993

  fn regex_comparison_string_coercion(

• datafusion/datafusion/optimizer/src/unwrap_cast_in_comparison.rs

  Line 168 in 7ebd993

  // https://github.com/apache/datafusion/issues/12180

  , etc

Expected behavior

Utf8View is supported and not coerced to Utf8 for all regexp functions including via binary operators.

Additional context

No response

[jayzhan211]

I think change the signature to TypeSignature::String can solve this issue. See #13301

[jayzhan211]

regex_comparison_string_coercion is the same as string_coercion, can we remove it and use string_coercion instead?

I saw the comment 👍