feat: Additional support for bidirectional communication between the debugger and MC

[anthonywongskyboxlabs]

Added support for sending requests that expect a response. Right now our main use cases for this are toggling on/off specific profilers.

The request flow:

1. Button (or some other UI element in a tab) calls sendDebuggerRequest, which posts a message to the webview host
2. handleDebuggerRequest is called, and further forwards the request to the debug session via await session.customRequest(...)
3. The request makes its way to MC, see request-manager.ts

Request format:

{ 
  "type": "debugger-request", 
  "request": { 
    "request_seq": 17, 
    "request": "Start CPU Profiler", 
    "args": { "foo": "bar" } 
  } 
} 

Eventually a response is received, and we walk back up the pipe, sending the response args back to the tab that requested it.

Format of response message being sent back to the debugger:

Naming of requests and responses

Originally I just wanted to call these requests and responses to keep them simple. However, those two keywords are already used in our QuickJS repo (example), so I didn't want to confuse them with this work.

[codyward-skybox]

Overall looks good to me, though it'd be nice to get eyes from someone with more experience in this part of the codebase.