[CodeQuality] Move 4 early-return rules to code quality set

[TomasVotruba]

These 4 rules clean up local code quality rather than enforce the early-return coding style. Move their set registration from early-return to CodeQualityLevel::RULES (right after InlineArrayReturnAssignRector, same "assign then return" family).

Set membership only - the rule classes stay in Rector\EarlyReturn\*, no namespace change.

RemoveAlwaysElseRector:

 class SomeClass
 {
     public function run($value)
     {
         if ($value) {
             throw new \InvalidStateException;
-        } else {
-            return 10;
         }
+
+        return 10;
     }
 }

ChangeIfElseValueAssignToEarlyReturnRector:

 class SomeClass
 {
     public function run()
     {
         if ($this->hasDocBlock($tokens, $index)) {
-            $docToken = $tokens[$this->getDocBlockIndex($tokens, $index)];
-        } else {
-            $docToken = null;
+            return $tokens[$this->getDocBlockIndex($tokens, $index)];
         }

-        return $docToken;
+        return null;
     }
 }

PreparedValueToEarlyReturnRector:

 class SomeClass
 {
     public function run()
     {
-        $var = null;
-
         if (rand(0, 1)) {
-            $var = 1;
+            return 1;
         }

         if (rand(0, 1)) {
-            $var = 2;
+            return 2;
         }

-        return $var;
+        return null;
     }
 }

ReturnEarlyIfVariableRector:

 class SomeClass
 {
     public function run($value)
     {
         if ($value) {
-            $variable = 'yes';
-        } else {
-            $variable = 'no';
+            return 'yes';
         }

-        return $variable;
+        return 'no';
     }
 }

One unrelated hunk: InlineConstructorDefaultToPropertyRector had a pre-existing ECS violation on main (missing space in an arrow fn); composer fix-cs corrected it, so it rides along.