feat: ftl schema diff

[gak]

Fixes #1989

ftl schema diff --help
Usage: ftl schema diff <other-endpoint> [flags]

Print any schema differences between this cluster and another cluster. Returns
an exit code of 1 if there are differences.

Arguments:
  <other-endpoint>    Other endpoint URL to compare against.

  --endpoint=http://127.0.0.1:8892     FTL endpoint to bind/connect to ($FTL_ENDPOINT).
  --color    Enable colored output regardless of TTY.

• Compares <other-endpoint> vs --endpoint into a unified diff with color.
• Exits with 1 if there is a difference.
• Detects tty and will not emit ANSI unless --color is passed in.

[worstell]

awesome!

(oof sorry i accidentally closed, meant to approve 😅)