Modernize Drush command.

Problem/Motivation

In order to keep up with Drush development, I think we should update the config-distro-update command to be more in line with the future of drush.

Proposed resolution

Use CLI attributes instead of DocBlock annotations https://www.drush.org/12.x/commands/
Use Drush Format options https://github.com/consolidation/output-formatters
Change command name from config-distro-update to config-distro:update
Add config-distro:list-changes command
Add config-distro:update --mode=merge
Add config-distro:update --mode=partial-reset
Add config-distro:update --mode=full-reset