Add colored output to zfs list

Use a bold header row and colorize the AVAIL column based on
the used space percentage of volume.

We define these colors:

• when > 80%, use yellow
• when > 90%, use red

Reviewed-by: WHR <msl0000023508@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ethan Coe-Renner <coerenner1@llnl.gov>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes #14621
Closes #14350