chore(rest): fix middleName null value and add CHANGELOG references (#493)

- Correct middleName from empty string to null in PUT request
- Add issue reference to REST client CHANGELOG entries

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: nanotaboada

CHANGELOG.md

@@ -44,8 +44,8 @@ This project uses famous football coaches as release codenames, following an A-Z
 
 ### Added
 
-- `rest/players.rest` file covering all CRUD operations, compatible with the VS Code REST Client extension
-- `humao.rest-client` added to `.vscode/extensions.json` recommendations
+- `rest/players.rest` file covering all CRUD operations, compatible with the VS Code REST Client extension (#493)
+- `humao.rest-client` added to `.vscode/extensions.json` recommendations (#493)
 - UUID v4 primary key for the `players` table, replacing the previous integer PK (#66)
 - `PlayerRequestModel` Pydantic model for POST/PUT request bodies (no `id` field) (#66)
 - `PlayerResponseModel` Pydantic model for GET/POST response bodies (includes `id: UUID`) (#66)
@@ -71,7 +71,7 @@ This project uses famous football coaches as release codenames, following an A-Z
 
 ### Removed
 
-- `postman_collections/` directory replaced by `rest/players.rest`
+- `postman_collections/` directory replaced by `rest/players.rest` (#493)
 
 ### Fixed
 

rest/players.rest

@@ -78,7 +78,7 @@ Content-Type: application/json
 
 {
   "firstName": "Emiliano",
-  "middleName": "",
+  "middleName": null,
   "lastName": "Martínez",
   "dateOfBirth": "1992-09-02T00:00:00.000Z",
   "squadNumber": 23,