Sync rescript-editor-support (#99)

* Sync rescript-editor-support

Sync rescript-editor-support to commit rescript-lang/rescript-editor-support@ae455c7

Since release 1.0.5:

#### New features
- Add support for autocomplete for pipe-first `foo->`: the type of `foo` is used to determine the module to take completions from.
- Add support for autocomplete for decorators such as `@module` and `@val`.
- Add support for autocomplete of labelled arguments `foo(~label... )`.
- Add support for @deprecated attributes in autocomplete and hover.
- Support for upcoming `rescript` npm package for the compiler. Looks for `rescript` in addition to `bs-platform` in `node_modules`.

#### Fixes

- Fix issue for uncurried functions where the internal definition of `Js.Fn.arity` is shown on hover. (See rescript-lang/rescript-editor-support#62).
- Fix type hint when hovering over labeled arguments of components (See rescript-lang/rescript-editor-support#63).
- Fix issue where values declared with type annotation would not show up in autocomplete, and would show no doc comment on hover. (See #72).
- Fix hover on definitions inside a react component module, or whenever multiple definitins for the same value exist in the module (See rescript-lang/rescript-editor-support#67).
- Fix autocomplete issue where multiple open's were considered in the wrong priority order (See rescript-lang/rescript-editor-support#72).
- Autocomplete: add support for `open!` in addition to `open`.

* Don't show deprecated message on hover.

Sync up with rescript-lang/rescript-editor-support@03ee0d9