Feature Request - Matching, no double indent (with/without leading vert)

[strega-nil]

I'd like to be able to write code like this:

match foo {
| Bar(...) => ...,
| Baz(...) => ...,
}

it's also possible that some might not want to use leading verts?

match foo {
Bar(...) => ...,
Baz(...) => ...,
}

but that's outside of my need.

[ytmimi]

closing in favor of #2937