This space breaks when upgrading bazelisk on Windows.
Somehow, a space inside the argument messes up some argument-parsin
somewhere. Porbably due to Windows argument parsing
being not well-defined in how it splits a string into argv.
Removing the space works around the problem.
If the space is included, cmake suddenly can't find the bazelisk
binary anymore, despite happily executing `info output_base` earlier.
A cmake generator in bazel is introduced allowing to import the Swift
extractor as a CMake project while keeping Bazel files as the source of
truth for the build.
Using the CMake project:
* requires bazel and clang to be installed and available on the command
line
* does not require a previous bazel build, however
* will require a CMake reconfiguration for changes to generated code
(like changes to the schema)
