Summarise fixable replacements in analysis output

[43081j]

If we detect any replacements we have codemods for, we should show an ESLint style summary:

10 errors, 12 warnings, 6 fixable by --migrate

Open to suggestions on the wording and if we show total fixable or we show it per level:

10 errors (3 fixable), 12 warnings (4 fixable)

[janis-me]

(new here, just throwing my thoughts out there)

I would show the total number. If you trust it to fix one kind of issue, you likely trust it to fix all of them. So if you run "migrate" anyways, you don't really care about the issue type.

The output of migrate should show more details then.

[43081j]

that's true

since we actually have a migrate command rather than a flag, its more like this i think:

10 errors, 12 warnings (6 fixable by migrate)

then if we ever introduce another command that mutates things, we could say 6 fixable by migrate, 4 fixable by X