Merge SwitchStatementWithSingleDefaultInspection into SwitchStatementWithTooFewBranches

Fixes IDEA-199499 Improve "Replace 'switch' with 'if'" action and make it a quick-fix for "Switch has too few branches"
Now default is not counted as branch in SwitchStatementWithTooFewBranches

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/convertSwitchToIf/afterString.java

@@ -4,11 +4,11 @@ class X {
       //comment1
       //comment4
       //comment6
+      //comment7
       //comment8
       if ("case1".equals(value)) {//comment2
           //comment3
       } else if ("case2".equals(value)) {//comment5
-      } else {//comment7
       }
   }
 }