feat: Add new feature to handle possible statuses retrieval

[athy125]

A new feature to the getPossibleStatuses method in the StatusAPI class. The method has been updated to cache the retrieved possible statuses locally using a private field #cachedPossibleStatuses.

This change improves performance by reducing unnecessary API calls and allows faster access to the possible statuses when needed, the getPossibleStatuses method now returns the cached statuses if available, and only fetches from the provider when the cache is empty or invalidated.

[ozyx]

Thank you so much for your contribution! If you haven't already, please complete and submit a Contributor License Agreement (CLA). This is required before we can approve/merge your code. Thanks again, we will be taking a look at this shortly!

[ozyx]

Looks like this is failing due to a build-time error:

ERROR in ./src/api/user/StatusAPI.js 32:9
Module parse failed: Private field '#cachedPossibleStatuses' must be declared in an enclosing class (32:9)
You may need an appropriate loader to handle this file type, currently no loaders are configured to process this file. See https://webpack.js.org/concepts#loaders
|     this.#userAPI = userAPI;
|     this.#openmct = openmct;
>     this.#cachedPossibleStatuses = null;
| 
|     this.onProviderStatusChange = this.onProviderStatusChange.bind(this);

[ozyx]

Please resolve the build errors and re-open the PR. Closing for now.