Problem:

Neovim will not build for ARM64 using MSVC due to misconfigured
gettext dependency build settings.

Solution:

Fix the dependency build settings for gettext when building with MSVC.

Problem: Installing treesitter parser is hard (harder than
climbing to heaven).

Solution: Add optional support for wasm parsers with `wasmtime`.

Notes:

* Needs to be enabled by setting `ENABLE_WASMTIME` for tree-sitter and
  Neovim. Build with
  `make CMAKE_EXTRA_FLAGS=-DENABLE_WASMTIME=ON
  DEPS_CMAKE_FLAGS=-DENABLE_WASMTIME=ON`
* Adds optional Rust (obviously) and C11 dependencies.
* Wasmtime comes with a lot of features that can negatively affect
  Neovim performance due to library and symbol table size. Make sure to
  build with minimal features and full LTO.
* To reduce re-compilation times, install `sccache` and build with
  `RUSTC_WRAPPER=<path/to/sccache> make ...`

Problem: Adding support for modern Nvim features (reflow, OSC 8, full
utf8/emoji support) requires coupling libvterm to Nvim internals
(e.g., utf8proc).

Solution: Vendor libvterm at v0.3.3.

Problem: Neovim bundles treesitter parsers for bash and python but does
not use them by default. This dilutes the messaging about the bundled
parsers being required for functionality or reasonable out-of-the-box
experience. It also increases the risk of query incompatibilities for no
gain.

Solution: Stop bundling bash and python parser and queries.

utf8proc contains all the data which is currently in
unicode_tables.generated.h internally, but in quite a different format.
Ideally unicode_tables.generated.h should be removed as well so we rely
solely on utf8proc. We want to avoid a situation where the possibility
of unicode mismatch occurs, e.g a distro using both unicode 12 and
unicode 13.

This allows us to skip generating them during our build process.

Passing `CMAKE_POLICY_DEFAULT_CMP0092=NEW` to all dependencies is
simpler than setting it manually in each file.