Generic/AbstractClassNamePrefix: improve code coverage and clean up tests

Test improvements:
* Adjust some existing tests to have comments and new lines in unexpected places.
* Adjust some existing tests to include extended classes and implemented interfaces.
* Add tests with `final` and `readonly` class modifier keywords.
* Make some tests more descriptive by making the class name reflect what is being tested.
* Add a few comments to pre-existing tests to clarify why they exist.
* Add a separate test case file with a live coding/parse error test.
* Remove some code snippets which weren't testing anything.

Clean up the test file:
* Remove redundant whitespace in the test case file.
* Use proper punctuation in comments in test case file.

Author: rodrigoprimo

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

@@ -1,59 +1,45 @@
 <?php
 
-abstract class IncorrectName // error
-{
+abstract class IncorrectName {} // Error.
 
-}
-
-abstract class AbstractCorrectName
-{
-
-}
+abstract class AbstractCorrectName {}
 
-abstract class IncorrectNameAbstract // error
-{
+abstract class IncorrectNameAbstract {} // Error.
 
-}
-
-abstract class InvalidNameabstract // error
-{
-
-}
+abstract
+    /*comment*/
+    class
+    InvalidNameabstract
+    extends
+    BarClass {} // Error.
 
-abstract class IncorrectAbstractName // error
-{
-
-}
+abstract class /*comment*/ IncorrectAbstractName {} // Error.
 
+// Anonymous classes can't be declared as abstract (and don't have a name anyhow).
 $anon = new class {};
 
-class AbstractClassName
-{
-
-}
+// Make sure that if the class is not abstract, the sniff does not check the name.
+class AbstractClassName {}
 
+// Class name is always checked, doesn't matter if the class is declared conditionally.
 if (!class_exists('AbstractClassCorrectName')) {
-    abstract class AbstractClassCorrectName
-    {
-
-    }
+    abstract class AbstractClassCorrectName {}
 }
 if (!class_exists('ClassAbstractIncorrectName')) {
-    abstract class ClassAbstractIncorrectName // error
-    {
-
-    }
+    abstract class ClassAbstractIncorrectName implements FooInterface {} // Error.
 }
 
-$abstractVar = '';
+$var = 'abstract class TextStringsAreDisregarded';
+
+class NotAnAbstractClassSoNoPrefixRequired {}
 
-$var = 'abstract class IncorrectNameButOk';
+abstract class abstractOkCaseOfPrefixIsNotEnforced {}
 
-$abstracVar = '';
+final class FinalClassShouldNotTriggerWarning {}
 
-class NameAbstractBar {}
+readonly class ReadonlyClassShouldNotTriggerWarning {}
 
-abstract class abstractOkName
-{
+abstract readonly class AbstractReadonlyClassWithPrefixShouldNotTriggerWarning {}
 
-}
+abstract readonly class ReadonlyAbstractClassShouldTriggerWarningWhenPrefixIsMissingA {} // Error.
+readonly abstract class ReadonlyAbstractClassShouldTriggerWarningWhenPrefixIsMissingB {} // Error.

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

@@ -0,0 +1,7 @@
+<?php
+
+// Intentional parse error (no class name).
+// This should be the only test in this file.
+// Testing that the sniff is *not* triggered.
+
+abstract class

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

@@ -35,10 +35,12 @@ public function getErrorList($testFile='')
         case 'AbstractClassNamePrefixUnitTest.1.inc':
             return [
                 3  => 1,
-                13 => 1,
-                18 => 1,
-                23 => 1,
-                42 => 1,
+                7  => 1,
+                11 => 1,
+                16 => 1,
+                29 => 1,
+                44 => 1,
+                45 => 1,
             ];
         default:
             return [];