Remove unnecessary continue/return hint should handle rule cases and switch expressions.

[lahodaj]

The RemoveUnnecessary hint crashes on code like:

switch (...) {
   case 0 -> { return ; }
}

with exceptions like:

Caused by: java.lang.AssertionError
	at org.netbeans.modules.java.hints.control.RemoveUnnecessary.unnecessaryReturnContinue(RemoveUnnecessary.java:175)
	at org.netbeans.modules.java.hints.control.RemoveUnnecessary.unnecessaryReturn(RemoveUnnecessary.java:99)

This patch adds handling for rule cases and switch expressions.

[mbien]

looks good, thanks for updating this hint.

edit: while testing I found another issue in a different switch hint #7973