Generate column SQL for char(36) in postgres schema

Don't omit length for 36 byte length CHAR columns. This is likely an
artifact of how UUID columns were handled in the past.

Fixes #13167

src/Database/Schema/PostgresSchema.php

@@ -399,7 +399,7 @@ class PostgresSchema extends BaseSchema
                 $type = ' CHAR';
             }
             $out .= $type;
-            if (isset($data['length']) && $data['length'] != 36) {
+            if (isset($data['length'])) {
                 $out .= '(' . (int)$data['length'] . ')';
             }
         }

tests/TestCase/Database/Schema/PostgresSchemaTest.php

@@ -177,6 +177,10 @@ SQL;
                 ['type' => 'string', 'fixed' => true, 'length' => 10]
             ],
             [
+                ['type' => 'CHAR(36)'],
+                ['type' => 'string', 'fixed' => true, 'length' => 36]
+            ],
+            [
                 ['type' => 'CHARACTER(10)'],
                 ['type' => 'string', 'fixed' => true, 'length' => 10]
             ],
@@ -696,6 +700,11 @@ SQL;
                 '"id" CHAR(32) NOT NULL'
             ],
             [
+                'title',
+                ['type' => 'string', 'length' => 36, 'fixed' => true, 'null' => false],
+                '"title" CHAR(36) NOT NULL'
+            ],
+            [
                 'id',
                 ['type' => 'uuid', 'length' => 36, 'null' => false],
                 '"id" UUID NOT NULL'
@@ -717,6 +726,11 @@ SQL;
             ],
             [
                 'title',
+                ['type' => 'string', 'length' => 36],
+                '"title" VARCHAR(36)'
+            ],
+            [
+                'title',
                 ['type' => 'string', 'length' => 255, 'null' => false, 'collate' => 'C'],
                 '"title" VARCHAR(255) COLLATE "C" NOT NULL'
             ],