Use HAL as contributed module for REST Example

Problem/Motivation

https://www.drupal.org/project/examples/issues/3340880 got Examples module compatible with Drupal 10, but this won't work well for our dev environments where we have REST Example installed, as it depends on HAL which has been removed from D10. A contrib version exists at https://www.drupal.org/project/hal which will fit the bill, but we'll need to patch the module to handle it.

Steps to reproduce

1. Start with Drupal 9
2. Install REST Example
3. Try upgrading to Drupal 10

Proposed resolution

Use the contrib version of HAL instead of the version from core.

Remaining tasks

Patch the project, using drupal/hal as a top-level dependency of Examples.

User interface changes

None.

API changes

None.

Data model changes

None.