feature: use axum

[bc-micah]

What?

• use axum framework
• working open telemetry tracing configuration and instructions
• simplified state extraction using axum extractor
• graceful shutdown of the server and tracing subscriber
• use async drop trait to shutdown tracing subscriber in tests

Why?

• take advantage of tower middleware
• allows us to debug easier
• to make sure spans are not discarded after test run or if server is shutdown

Testing/Proof

tracing:

all tests pass