Generic/CamelCapsFunctionName: improve code coverage and remove unnecessary return

The `return;` is unnecessary as the last statement in a method.

Test improvements:
* Add separate test case files with live coding/parse error tests.
* Add tests verifying sand safeguarding that the name of methods in interfaces is also checked.
* Add tests covering the public `strict` property which can be toggled from within rulesets.

Author: rodrigoprimo

src/Standards/Generic/Sniffs/NamingConventions/CamelCapsFunctionNameSniff.php

@@ -168,7 +168,6 @@ protected function processTokenWithinScope(File $phpcsFile, $stackPtr, $currScop
             }
 
             $phpcsFile->recordMetric($stackPtr, 'CamelCase method name', 'no');
-            return;
         } else {
             $phpcsFile->recordMetric($stackPtr, 'CamelCase method name', 'yes');
         }

src/Standards/Generic/Tests/NamingConventions/CamelCapsFunctionNameUnitTest.1.inc

@@ -183,3 +183,22 @@ enum Suit: string implements Colorful, CardGame {
     public function parseMyDSN() {}
     public function get_some_value() {}
 }
+
+interface MyInterface {
+    public function getSomeValue();
+    public function get_some_value();
+}
+
+class MyClass {
+    // phpcs:set Generic.NamingConventions.CamelCapsFunctionName strict false
+    function strictFOrmatDIsabled() {}  // Ok.
+    // phpcs:set Generic.NamingConventions.CamelCapsFunctionName strict true
+
+    function strictFOrmatIsENabled() {}  // Not ok.
+}
+
+// phpcs:set Generic.NamingConventions.CamelCapsFunctionName strict false
+function strictFOrmatDIsabled() {}  // Ok.
+// phpcs:set Generic.NamingConventions.CamelCapsFunctionName strict true
+
+function strictFOrmatIsENabled() {}  // Not ok.

src/Standards/Generic/Tests/NamingConventions/CamelCapsFunctionNameUnitTest.2.inc

@@ -0,0 +1,9 @@
+<?php
+
+// Intentional parse error (missing method name).
+// This should be the only test in this file.
+// Testing that the sniff is *not* triggered.
+
+class My_Class {
+    public function {}
+}

src/Standards/Generic/Tests/NamingConventions/CamelCapsFunctionNameUnitTest.3.inc

@@ -0,0 +1,7 @@
+<?php
+
+// Intentional parse error (missing function name).
+// This should be the only test in this file.
+// Testing that the sniff is *not* triggered.
+
+function

src/Standards/Generic/Tests/NamingConventions/CamelCapsFunctionNameUnitTest.php

@@ -76,6 +76,9 @@ public function getErrorList($testFile='')
                 180 => 2,
                 183 => 1,
                 184 => 1,
+                189 => 1,
+                197 => 1,
+                204 => 1,
             ];
         default:
             return [];