Union types should contain a space around the vertical bar

[MrMarCode]

It was noted that union types should have a space around the vertical bar separator. For example: client: Got|Promise<Got> should get flagged and should expect client: Got | Promise<Got> instead.

[MatheusBaldi]

@MrMarCode there is a rule for this behavior (I guess it's actually for the bitwise or operator, but works here as well) space-infix-ops from eslint, but it has been deprecated together with many other formatting rules and moved to another package, the eslint stylistic.
In the docs for the typescript-eslint space-infix-ops there are two issues referenced that talk about this change, but it also says the old rules would continue to work. For the space-infix-ops though, the rule was not working, so I changed them to use the eslint stylistic plugins, which was already installed and not being used, and it worked.

I don't know for now if all the rules must be update to use stylistic, but I've migrated and tested all of them locally and they're working. I'll open a draft PR with the changes. Any suggestion is welcome.