Add flag to put guildellm into "non-interactive" mode

[sjmonson]

Guidellm's use of terminal control characters in its console output can cause issues for non-interactive consoles such as when run by another tool. This can be solved by adding a flag to disable clearing the screen between updates.

[markurtz]

Closing out as #96 added --disable-progress which will remove the progress display that was clearing the screen. Additionally, --disable-console-outputs is added as well enabling minimal output to the console. Feel free to reping if you feel like that won't work / we need to expand past that.