The translation step prolongs the build time too much to be enabled by
default. Enable it by passing cmake flag `ENABLE_TRANSLATIONS=ON`.

Problem:  Unknown key mappings listed in substitute confirm message.
Solution: Include hints as to what the key mappings do.

closes: vim/vim#16144

https://github.com/vim/vim/commit/336fb22eaef7977741712d0c4735fc6d65428a4f

Problem:
Noise in stderr from src/nvim/po/CMakeLists.txt during build:

    48 substitutions on 48 lines
    "optwin.js" "optwin.js" 1299L, 57582B written
    385 substitutions on 385 lines
    "nvim.pot" "nvim.pot" 9318L, 180177B written

Solution:
Run with `-c silent source` instead of `-S`.

Problem:
The message E325 displays “vim -r” to recover the file.

Solution:
Change the message to display “nvim -r” instead of “vim -r”.

Problem:  spell completion message still wrong in translations
          (after 9.1.0512)
Solution: Update translation files with the new message
          (Kyle Kovacs)

closes: vim/vim#15113

https://github.com/vim/vim/commit/68f5ceddca2ec2d591b9180020c95bb86bf6d3d2

Co-authored-by: Kyle Kovacs <kkovacs@diconfiberoptics.com>

Co-authored-by: ite-usagi <77563904+ite-usagi@users.noreply.github.com>
Co-authored-by: v-sim <56476039+v-sim@users.noreply.github.com>
Co-authored-by: Evgeni Chasnovski <evgeni.chasnovski@gmail.com>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>
Co-authored-by: Quico Augustijn <quico.public@gmail.com>
Co-authored-by: nhld <nahnera@gmail.com>
Co-authored-by: francisco souza <108725+fsouza@users.noreply.github.com>

- remove "ran-" prefix from touch files as it's redundant since the
  they're already in the directory named `touches`.
- Include `contrib` when formatting with `make formatlua`.
- Use TARGET_FILE generator expression instead of assuming the
  executable location.
- reuse logic that determines whether to use lua or luajit.
- add translations to the `nvim` target.

Makefile improvements:
- rename variable `CMAKE_PRG` to `CMAKE` to make it more consistent with
  the builtin `MAKE` variable.
- stop propagating flags to generator. Users should use cmake for
  non-standard use cases.
- remove `+` prefix from targets. If the user for whatever reason wants
  to dry-run a target then they should be able to.

This distinction is important for correct dependency management, as the
nvim binary is used to create some runtime files. The nvim binary (and
the target to build it) is thus called `nvim_bin` and the target to
build all of nvim (binary+runtime) is called `nvim`.