`section-underline-matches-section-length` (`D409`) should warn on all titles instead of a list of known ones

it seems that this rule only cares about specific titles ("Example", "Parameters", "Raises", "Returns") but i don't see why it can't just check every title

```py
def foo(): # error
"""
example:
-----------
asdf
"""

def bar(): # no error
"""
asdf:
--------
asdf
"""
```

https://play.ruff.rs/a10dd179-6047-43c4-97b1-5083e68008a1

Start with the implementation of rule D409 (`section-underline-matches-section-length`) and reproduce the examples in the linked Ruff Playground. Update the rule so an underline mismatch is reported for arbitrary section titles, then verify that the demonstrated `foo` case warns while the `bar` case does not.

Written by the indexing model from the issue text.