Emit compiler errors and warnings via `tracing` logs in order for more control over filtering, output target, etc

`forc` uses `tracing` for logging. This is quite useful for gaining control over how output is handled. In particular, it makes it much easier to filter certain output.

Currently, `forc-util`'s `format_err` and `format_warning` functions that are used for formatting and emitting output write directly to stdout. We should change these to emit output via `tracing`'s logging feature.

Compile errors should likely be emitted via `error!`, and warnings via `warn!`.

Blocked by FuelLabs/sway#1661.

Related FuelLabs/sway#2362, FuelLabs/sway#2373.