Improve ``zigup default`` and ``zigup list`` output

[iddev5]

Commit message:

Default command now also points to the actual directory if default compiler is master.

List command now also marks which one is the master also also marks the default compiler with (default).

Few doubts:

1. about the option to opt in to show only version without external info, should be apply to only list or both list as well as default commands?
2. I m not sure if the logic to check master is correct for windows. If I get time, I will look into how it has been done in the other parts.

This PR till now only rebases and makes a small edit since the issue was created.

Closes #35

[iddev5]

I think all changes have been resolved.