[BUG]: properly catch and propogate panics in component handlers

[codetheweb]

Description of changes

In Rust, panics (should) always semantically indicate a program bug. By default panics will terminate the current thread. This makes sense for single-tenant programs, e.g. CLI tools, GUI programs, etc.

However, if we assume that most program bugs are triggered via user-provided input, this behavior is much less desirable for multi-tenant systems. A bad code path triggered by a small percentage of users should not cause service degradation for all users.

Given this, I decided to continue down the path of catching panics rather than crashing the entire process upon a panic.

This approach (I assume because of similar reasoning) is also taken by tonic, our gRPC server, which catches panics at the gRPC service handler layer. Tokio also catches panics at the task level.

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This PR cleans up panic-related code and adds logic to catch panics inside component handlers (this is where we have previously observed hangs because of improperly handled panics).

Test plan

How are these changes tested?

• Tests pass locally with pytest for python, yarn test for js, cargo test for rust

Also tested by inserting a panic! into a compaction handler and observing that the error correctly propagated and compaction continued to progress (previously hung the process).

Documentation Changes

Are all docstrings for user-facing APIs updated if required? Do we need to make documentation changes in the docs repository?

n/a

[github-actions]

Reviewer Checklist

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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 (Readability, Modularity, Intuitiveness)