More object store documentation.

[jmchilton]

Link out to relevant training materials for older documentation and add some documentation for User Selectable Storage (#14073).

The object store sample now includes two smaller use cases around User Selectable Storage - namely details about how to setup scratch storage and how to setup an experimental storage selection (e.g. iRODS). This includes object store tags I would use to communicate this data to the user, a discussion of cleaning up short term storage, and description of private storage and having different storage options using separate quotas.

I've also dumped in the big MSI-based example from #14073 because it demonstrates a bigger example with more factors and richer descriptions.

If anyone, especially admin-focused folx, found #14073 too sprawling to review these examples give admins something small to digest and give indications about how servers will need to be updated to leverage this new functionality.

How to test the changes?

(Select all options that apply)

• I've included appropriate automated tests.
• This is a refactoring of components with existing test coverage.
• Instructions for manual testing are as follows:
  1. [add testing steps and prerequisites here if you didn't write automated tests covering all your changes]

License

• I agree to license these and all my past contributions to the core galaxy codebase under the MIT license.

[bgruening]

Thanks John!