[DoctrineBridge] Add NAME const for UID types

This allows to refer to the constant instead of an "arbitrary" string.
For example:

#[ORM\Column(type: UuidType::NAME)]
private $foo;

Doctrine already does it this way in its documentation.

The name of the constant is taken from the already existing
`Symfony\Bridge\Doctrine\Tests\PropertyInfo\Fixtures\DoctrineFooType`
class, where a constant with a similar purpose already exists (albeit
this one is `private`).

Author: marcelsiegert

CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+6.2
+---
+
+ * Add `NAME` constant to `UlidType` and `UuidType`
+
 6.0
 ---
 

Types/UlidType.php

@@ -15,9 +15,11 @@
 
 final class UlidType extends AbstractUidType
 {
+    public const NAME = 'ulid';
+
     public function getName(): string
     {
-        return 'ulid';
+        return self::NAME;
     }
 
     protected function getUidClass(): string

Types/UuidType.php

@@ -15,9 +15,11 @@
 
 final class UuidType extends AbstractUidType
 {
+    public const NAME = 'uuid';
+
     public function getName(): string
     {
-        return 'uuid';
+        return self::NAME;
     }
 
     protected function getUidClass(): string