Add some projects to test-extra (#1326)
Add some projects to test-extra (#1326)

The projects are kept commented-out:

- Coq: It's a big project and OCamlformat seems kept uptodate.
  Configuration based on profile `ocamlformat` and rarely used options.
- Mirage, Alcotest and Citty: Using conventional profile.
ocaml-ppx/ocamlformat,ocaml-ppx/ocamlformat,ocaml-ppx/ocamlformat