Better error message for missing methods on objects

[amiralies]

They are called fields in docs. I think we should call them fields in errors too. for example. This error

This expression has type user, it has no method lastName

should be

This expression has type user, it has no field lastName

[yanchen036]

Looks like it only need to modify these two lines, Am I right? https://github.com/rescript-lang/syntax/blob/master/compiler-libs-406/typecore.ml#L4985 https://github.com/rescript-lang/syntax/blob/master/compiler-libs-406/typecore.ml#L4991

[cristianoc]

In the rescript-compiler repo not here.

[mvaled]

I think this can be closed. These messages no longer read like that in master.