Improving logging and status display

[geofflamrock]

Improves logging and status output:

• Adds new --debug option to allow separation between debug (e.g. "rebasing my-feature-branch onto main") and verbose logging (e.g. "running command 'git ...'").
• Change logging levels of some message to make normal usage not so noisy.
• Only log command output in verbose mode.
• Wrap long running actions in a status display to make it clearer what is happening.
• Add "success" messages to show completed progress during sync command