Inclusion of rename organization api (#33303)

This adds an endpoint (`/orgs/{org}/rename`) to rename organizations.

I've modeled the endpoint using the rename user endpoint --
`/admin/users/{username}/rename` -- as base.

It is the 1st time I wrote a new API endpoint (I've tried to follow the
rename users endpoint code while writing it). So feel free to ping me if
there is something wrong or missing.

Resolves #32995

---------

Signed-off-by: Bruno Sofiato <bruno.sofiato@gmail.com>
Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

templates/swagger/v1_json.tmpl

@@ -2991,6 +2991,46 @@
         }
       }
     },
+    "/orgs/{org}/rename": {
+      "post": {
+        "produces": [
+          "application/json"
+        ],
+        "tags": [
+          "organization"
+        ],
+        "summary": "Rename an organization",
+        "operationId": "renameOrg",
+        "parameters": [
+          {
+            "type": "string",
+            "description": "existing org name",
+            "name": "org",
+            "in": "path",
+            "required": true
+          },
+          {
+            "name": "body",
+            "in": "body",
+            "required": true,
+            "schema": {
+              "$ref": "#/definitions/RenameOrgOption"
+            }
+          }
+        ],
+        "responses": {
+          "204": {
+            "$ref": "#/responses/empty"
+          },
+          "403": {
+            "$ref": "#/responses/forbidden"
+          },
+          "422": {
+            "$ref": "#/responses/validationError"
+          }
+        }
+      }
+    },
     "/orgs/{org}/repos": {
       "get": {
         "produces": [
@@ -24207,6 +24247,22 @@
       },
       "x-go-package": "code.gitea.io/gitea/modules/structs"
     },
+    "RenameOrgOption": {
+      "description": "RenameOrgOption options when renaming an organization",
+      "type": "object",
+      "required": [
+        "new_name"
+      ],
+      "properties": {
+        "new_name": {
+          "description": "New username for this org. This name cannot be in use yet by any other user.",
+          "type": "string",
+          "uniqueItems": true,
+          "x-go-name": "NewName"
+        }
+      },
+      "x-go-package": "code.gitea.io/gitea/modules/structs"
+    },
     "RenameUserOption": {
       "description": "RenameUserOption options when renaming a user",
       "type": "object",