Improve CatchClauseOnlyRethrows to support MultiCatch completely

[jevanlingen]

What's changed?

The recipe CatchClauseOnlyRethrows supports multiple exception types now completely.

What's your motivation?

Code like

try {
  // something
} catch (SomeException | SomeOtherException e) {
  throw e;
} catch (Exception e) {
  throw new WhateverException(e);
}

will currently be altered by the recipe, which is incorrect.

Checklist

• I've added unit tests to cover both positive and negative cases
• I've read and applied the recipe conventions and best practices
• I've used the IntelliJ IDEA auto-formatter on affected files

[MBoegers]

on it

[MBoegers]

small fixes for null and