feat: add archival memory GET, POST, DEL to REST API

[cpacker]

Add API routes for archival memory to allow for displaying + editing archival memory contents inside the chat UI.

Please describe the purpose of this pull request.

Adds the following API routes:

• get_agent_archival_memory (NOTE: punting to later PR)
  • paginated query of archival memory contents
  • TODO currently untested, does not work on chroma
• get_agent_archival_memory_all
  • unpaginated query of archival memory contents (returns ALL contents)
• insert_agent_archival_memory
  • insert a string into archival memory
  • returns a list of record IDs (list because the input may be chunked)
• delete_agent_archival_memory
  • delete an entry from archival memory

How to test

Note @sarahwooders this should really be rolled into a unit test but alas...

Example testing the routes:

• create new agent (empty archival)
• ask agent question about archival memory contents (gets answer wrong)
  • 
• list contents of archival memory (empty)
  • 
• insert into archival memory (via POST API)
  • 
• list contents of archival memory (non-empty)
  • 
• ask agent question about archival memory contents (gets answer correct)
  • 
• delete archival memory content
  • 
• list contents of archival memory (now empty again)
  • 

[sarahwooders]

lgtm!