Add:arrow_metadata() UDF

[xonx4l]

Which issue does this PR close?

Closes #19356

Rationale for this change

This PR implements the arrow_metadata UDF as requested in issue #19356.

What changes are included in this PR?

Added arrow_metadata UDF
Refactored Tests

Are these changes tested?

Yes.

Are there any user-facing changes?

Yes.

[Jefffrey]

I think we just need to add some documentation, see an example from arrow_typeof here:

datafusion/datafusion/functions/src/core/arrowtypeof.rs

Lines 25 to 42 in 2c3566c

	#[user_doc(
	doc_section(label = "Other Functions"),
	description = "Returns the name of the underlying [Arrow data type](https://docs.rs/arrow/latest/arrow/datatypes/enum.DataType.html) of the expression.",
	syntax_example = "arrow_typeof(expression)",
	sql_example = r#"```sql
	> select arrow_typeof('foo'), arrow_typeof(1);
	+---------------------------+------------------------+
	| arrow_typeof(Utf8("foo")) | arrow_typeof(Int64(1)) |
	+---------------------------+------------------------+
	| Utf8 | Int64 |
	+---------------------------+------------------------+
	```
	"#,
	argument(
	name = "expression",
	description = "Expression to evaluate. The expression can be a constant, column, or function, and any combination of operators."
	)
	)]

[xonx4l]

@Jefffrey Done.