Mosaic#39 add --debug flag

[denismaxim0v]

No description provided.

[TheLostLambda]

This is looking pretty good to me! I left one nitpick and it might be nice to have some tests, but I'll be honest, tests for this seem a bit challenging to write.

Regardless, thanks a ton for writing this up! I'll probably defer to @imsnif to make the final call though :)

[TheLostLambda]

Just a very tiny Rust nitpick, but for joining with an empty string, there is the .concat() method that might be a bit more idiomatic :)

[denismaxim0v]

Great, let me know what you end up with

[imsnif]

@denismaxim0v - this looks great to me. It will also be extremely helpful in debugging compatibility issues.
I played with this around a little on my machine and it definitely does the right thing. One can use these logs to debug issues by simply doing cat <logfile> inside a mosaic pane (and outside for comparison). The mosaic-logs folder is re-created on startup. All looks good.

@denismaxim0v - I think if you just apply @TheLostLambda's suggestion, we can merge this.

Thanks for this!