Since scap is now capable of deploying and compiling config files via jinja2, there needs to be some way to see a config-file diff before deploying a change.

Discussed in the cabal meeting notes

• Pass configuration diff from target back to deployer
• By default 1st target 1st deploy group
• Console syntax highlighting via pygments
• -a/--im-insane :) for all targets diff

Basis for this should be laid out in T109513 but the feature was lost in the shuffle.