[RHIDP-10148] Update Llama Stack to v0.2.22

[Jdubrick]

What does this PR do?:

• Updates to Llama Stack v0.2.22
• Moves off temporary dependency for lightspeed_stack_providers and moves to lightspeed_stack_providers==0.1.17
• Removed unused/unnecessary items from the run.yaml
• Added Files API to satisfy Llama Stack v0.2.22 requirements
• Updated definition of RAG vector_db to satisfy how Llama Stack v0.2.22 consumes it
  • Tested these with old versions of the RAG image as well, still works as expected
• Quick update to README

Which issue(s) this PR fixes:

https://issues.redhat.com/browse/RHIDP-10148

PR acceptance criteria:

Testing and documentation do not need to be complete in order for this PR to be approved. We just need to ensure tracking issues are opened and linked to this PR, if they are not in the PR scope due to various constraints.

• Tested and Verified

• Documentation (READMEs, Product Docs, Blogs, Education Modules, etc.)

How to test changes / Special notes to the reviewer:

[Jdubrick]

Converting to draft to investigate issue with /v2 endpoints after migration

[Jdubrick]

Closing in favour of https://issues.redhat.com/browse/RHIDP-11190 which will take us to Llama Stack v0.3.x