Move Tracing Configuration from Command Line Flags to Fendermint Config and Allow Hot Reloading

[karlem]

The issue: Currently, it is challenging to add tracing configuration to the Fendermint config for two reasons:

1. We set up the tracing subscriber before the configuration is loaded.
2. Changing the tracing subscriber once it is set is not easily doable with the tracing library.

As a workaround, we have implemented the tracing configuration via command line arguments.

The solution: We need to write a custom dynamic layer that will be able to load/change other layers so that we can support config changes after the tracing library has been set up.

For more details, refer to the tracing-subscriber layer documentation.