[BUGFIX] Fix else return for nested issue reporting

Reference: #1380 

Updates the no-else-return rule to display multiple errors in cases of nested violations of this rule, where before it was only showing the most interior violation and would not display the others until that one was fixed.

@nzakas Please review, thanks! I'm not convinced this is the best implementation, but it seems to satisfy all the use-cases I could think of.

Fixes #1369
The rule itself is actually implemented such that this can be achieved, but the default behavior requires @returns for all docs.  I don't know if that's an appropriate default, but it seems the choice for this project is to do so.