Parse and print braces around inline records

[anmonteiro]

This was brought up in #2336

[anmonteiro]

We should also fix this in the outcome printer when #2336 is in. I don't wanna have to deal with merge conflicts :)

[jordwalke]

This is great! It's a "minor version bump" change, which means it's a new feature that people might depend on in their code.

For example, for this we would bump the version from 3.4.1 to 3.5.0. No one's existing code will break (that would be a 4.x.x bump) but some people can write code that depends on the new feature so it's an y bump in x.y.z (that's called a "minor version" bump).

If John uses this feature in his code, he will need to specify in their package versions:

"@esy-ocaml/reason": ">= 3.5.0 < 4.0.0"

If Mary has a package that depends on "end of line comments" feature, she would have specified:

"@esy-ocaml/reason": ">= 3.4.0 < 4.0.0"

Because `3.4.0 added end of line comments.

And if those two people mixed their packages into an app, the package solver would know to use reason version 3.5.0 with your change. I just thought I'd write out the the steps of how I think through potential scenarios for breakage so other people understand what's behind versioning in Reason.