Requestable/Request Item API Endpoints

[spencerrlongg]

Description

This adds actions for creating and cancelling checkout requests, as well as adding new endpoints for the API to bring the functionality there. This should probably not be merged until #15893 is as it relies on the same pattern.

The only real change here I think is that the cancel functionality has been broken out into its own route and action for the GUI, whereas before it was combined into the same controller method. I also renamed the controller methods to keep it CRUD-y.

There are some tests written for the new API functionality, and all other tests are passing.

I wrote this a while ago so I might be forgetting some things, but I wanted to get #15893 open before opening this one, so please ask questions about anything that's unclear. :)

Fixes #SC-24347

Type of change

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

How Has This Been Tested?

Tests written.

Test Configuration:

• PHP version: 8.1
• MySQL version 8.1

[what-the-diff]

PR Summary

• Adding and Handling of Checkout Requests
  We have now implemented the classes CancelCheckoutRequestAction and CreateCheckoutRequestAction. These will respectively allow for the canceling and creating of requests for any specified asset.

• Asset and User Exceptions Management
  Two new exception cases have been added - AssetNotRequestable and UserDoestExistException. These account for situations where an asset cannot be requested or a user does not exist, providing necessary error handling.

• Improved Asset View and Request Handling
  Changes have been made to the ViewAssetsController and a new CheckoutRequest API Controller has been implemented. This is part of moving towards the new CheckoutRequest actions for handling asset requests and cancellations.

• Updates to Asset Model and Factory
  Updates for the Asset model have been implemented, specifically defining return types for better standardization. Additionally, we've enhanced the AssetFactory for more in-depth data creation during asset creation.

• Adjusted JavaScript Template and Routes
  The JavaScript Template has been updated to change the form action for canceling asset requests, aligning with the new API route syntax. Routes have been adapted and added to better handle storing and destroying checkout requests.

• Established Test Cases
  New test cases have been created for checking the functionality of creating and canceling asset requests. These will ensure the new features are working as expected, and catch any future regression issues.