Integrates HDK with the Rust tracing crate.
The functions and structs in this module do not need to be used directly.
hdk_extern! attribute on functions exposed externally all set the
WasmSubscriber as the global default.
This module defines a
trace::WasmSubscriber that forwards all tracing macro calls to another subscriber on the host.
The logging level can be changed for the host at runtime using the
WASM_LOG environment variable that works exactly as
RUST_LOG for other tracing.