feat: add repomap support for ocaml/ocaml_interface

[andreypopp]

Adds repo map support for .ml and .mli

Things I'm not sure about:

1. Should we have same tags files in both queries/tree-sitter-language-pack
queries/tree-sitter-languages?

2. I think we should be smarter and only use tags from .mli files if they are
   present. E.g. if test.ml and test.mli are both present in the repo — get
   atgs only from test.mli as this is the external interface of the Test
   module.

Depends on:

• feat: add ocaml/ocaml_interface languages Goldziher/tree-sitter-language-pack#25
• feat: specify ts lang for .ml/.mli grep-ast#19

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