[feature]: [test]: build tags for setting the global log level

[jharveyb]

Is your feature request related to a problem? Please describe.

Some of the make targets used in development like unit-trace don't actually enable trace-level logging, only the default level of info.

Describe the solution you'd like

Make targets that enable various log levels, similar to lnd. AFAICT this requires new build tags and possibly a /build dir?

https://github.com/lightningnetwork/lnd/tree/master/build

Describe alternatives you've considered

Tried to pass the log level via the test binary args but that failed. Build tags seem strictly better.