[ENH] Add rust assignmenment policy and config management

[HammadB]

Description of changes

Summarize the changes made by this PR.

• Improvements & Bug fixes
  • Adds the configurable trait for static configuration of components.
  • In rust, our pattern will be that a root worker configurable object is consumed by components implementing the "Configurable" trait. Structs can then initialize themselves if the valid config exists. DI dispatch will happen by adding a dispatch type in the config.rs method of each module (not included here). Without any fancy macro programming, I think this is the best way to do it.
  • Calling code can Box<dyn configurable> and pass in the worker config to any components in need of configuration.
• New functionality
  • Adds the rust assignment policy based on the python and go versions

Test plan

Added tests for booting the assignment policy config

• Tests pass locally with cargo test

Documentation Changes

None required. Feedback welcome on in-code documentation.

[HammadB]

Current dependencies on/for this PR:

• main
  • PR [CHORE] Initialize rust #1499
    • PR [ENH] Add Rust Configuration #1500
      • PR [CHORE] Add Rust CI & Basic Dockerfile #1504
        • PR [ENH] Add rust rendezvous hashing and errors #1508
          • PR [ENH] Add rust assignmenment policy and config management #1510 👈
            • PR [ENH] Add rust protobufs and conversion. Add build.rs, protobufs, and conversions #1513
              • PR [ENH] Add rust hnswlib bindings, index interface #1516
                • PR [ENH] Add component system + memberlist provider #1519
                  • PR [ENH] add Rust pulsar and topic management #1528
                  • PR [ENH] Rust SysDB #1529
                  • PR [ENH] Add rust message id conversion for pulsar #1531
                  • PR [ENH] Refactor system to allow mutable handles, wrapped messages, single M recievers #1539
                  • PR [ENH] Add ingest dispatch + scheduler + segment #1542
                  • PR [ENH] Add rust grpc server #1548

This stack of pull requests is managed by Graphite.

[github-actions]

Reviewer Checklist

Please leverage this checklist to ensure your code review is thorough before approving

Testing, Bugs, Errors, Logs, Documentation

• Can you think of any use case in which the code does not behave as intended? Have they been tested?
• Can you think of any inputs or external events that could break the code? Is user input validated and safe? Have they been tested?
• If appropriate, are there adequate property based tests?
• If appropriate, are there adequate unit tests?
• Should any logging, debugging, tracing information be added or removed?
• Are error messages user-friendly?
• Have all documentation changes needed been made?
• Have all non-obvious changes been commented?

System Compatibility

• Are there any potential impacts on other parts of the system or backward compatibility?
• Does this change intersect with any items on our roadmap, and if so, is there a plan for fitting them together?

Quality

• Is this code of a unexpectedly high quality (Readbility, Modularity, Intuitiveness)

[beggers]

Nice

[beggers]

Note to self: pub exports this trait from the crate. pub(crate) makes it usable anywhere within this crate.