Separate the field access function from an operator automatically

[jfmengels]

Quite often, I write code similar to the following:

result = someRecord|>.field

which then gets reformatted to

result =
    someRecord |>. field

which does not compile, because |>. is not a known operator.
This is "syntactically" the correct change, as even in the first case, the code does not compile for the same reason.

Since elm-format likes to fix syntax errors to help the user out without them noticing, I thought maybe it could also help them by reformatting to the following instead:

result =
    someRecord |> .field

I think the same thing would be worthwhile for <|, <<, >>, and potentially all operators.

This is my proposal:
When seeing code of the form <known operator>.<valid field name>, reformat it to <known operator> .<valid field name>.

AFAIK, there is only |. from Parser and Parser.Advanced which ends with a ., but since | is not a known operator, this wouldn't be ambiguous.

Since the number of operators is limited and has been stable for quite a while now, I think it would be reasonably safe to fix it the proposed way but you may righteously disagree, and that would be a good reason to decide against this proposal 👍

Thanks for all your work on elm-format! ❤️