LSP autocompletion not offering module type in the same file

There is no autocompletion help by the LSP to help with annotating the module type with a module type being a submodule in the same file. (The LSP helps annotating the module type, when the module type from another file is used.)

module type MT = {
  let x: int
  }

module M: //<-- Cursor is here, but LSP will not suggest MT

This may not be the most common case, but could add some convenience.

Note: This behavior was first stated in https://github.com/rescript-lang/rescript-vscode/issues/902, but was added as a separate issue for transparency.

Reproduce the reported completion gap with the ReScript snippet, placing the cursor after module M: while MT is defined in the same file. Compare this with completion for a module type imported from another file, then trace the LSP completion entry point that handles the two cases. Done means same-file module types are offered as completion suggestions without regressing cross-file suggestions.