Expr. simplification / rewrite: regex `.*foo.*`

### Is your feature request related to a problem or challenge?

SQL is a complex beast and sometimes users don't use the best tool for the job. A good example is:

```SQL
SELECT *
FROM t
WHERE c ~ '.*foo.*';
```

This regex will even get pushed down to the Parquet file filtering. However it effectively only means "`c` contains `'foo'`".

### Describe the solution you'd like

Extend the [regex simplification](https://github.com/apache/datafusion/blob/a026e7da2fe88f1923770ec3249c5f0e7b2ea6b0/datafusion/optimizer/src/simplify_expressions/regex.rs) and the [respective tests](https://github.com/apache/datafusion/blob/a026e7da2fe88f1923770ec3249c5f0e7b2ea6b0/datafusion/optimizer/src/simplify_expressions/expr_simplifier.rs#L3304-L3305) to rewrite `.*needle.*` to [`contains`](https://datafusion.apache.org/user-guide/sql/scalar_functions.html#contains).

### Describe alternatives you've considered

We could also rewrite this to `%foo%` (i.e. a `LIKE` statement)

### Additional context

\-

Start with datafusion/optimizer/src/simplify_expressions/regex.rs and the related tests in datafusion/optimizer/src/simplify_expressions/expr_simplifier.rs around lines 3304-3305. Run the existing expression simplifier tests, then verify that the regex form `.*needle.*` is rewritten to `contains` and that the new behavior is covered by tests.

Written by the indexing model from the issue text.