Regression in 13.9.0 after switching from JavadocStyle to SummaryJavadoc

Since checkstyle 13.9.0 we have to switch from JavadocStyle to SummaryJavadoc due to #20610

After the update to 13.9.0 we removed
```



```
in TreeWalker and replaced it with
```

```

Since this change we have more checkstyle errors because with JavadocStyle it was allowed to have an Empty summary if @param and/or @return was documented.

With JavadocStyle it was also possible to end a sentence with `.` or `?`.
With SummaryJavadoc javadocs like
```
/**
* Are you sure?
**/
boolean doSomehing = false;
```
are invalid.

It would be nice if SummaryJavadoc has an compatibility-option for the old behavior.

Start with the SummaryJavadoc implementation and its existing tests, then compare its handling of empty summaries and sentence-ending punctuation with the behavior described for JavadocStyle. Define the compatibility option's expected behavior for documented @param/@return tags and summaries ending in '?' or '.', and add tests showing the option works.

Written by the indexing model from the issue text.