[DeadCode] Handle consecutive equal case stmts on RemoveDuplicatedCaseInSwitchRector

[samsonasik]

Fixes rectorphp/rector#8867

[samsonasik]

Fixed 🎉 /cc @dionis-svk

[samsonasik]

All checks have passed 🎉 @TomasVotruba I am merging it ;)

[samsonasik]

It seems still have issue with multiple equal case consecutive but jump different stmts result:

class ConsecutiveEqualCaseStmts3
{
    public function run()
    {
      $item = 'a';
      switch ($item) {
        case 'a':
        case 'b':
          return 'val1';
        case 'c':
          return 'val2';
        case 'd':
        case 'e':
          return 'val5';
        case 'f':
        case 'g':
          return 'val2';
        case 'h':
          return 'val2';
        case 'i':
          return 'val3';
      }
      return $item;
    }
}

i will check if it resolvable or just skip it as too complex to handle :)

[samsonasik]

#6393