common: extract options into yaml

common: extract options into yaml

extract the options in common/options.cc into separate .yaml.in
files, and preprocess them using CMake before translating them into .cc
files using a python script.

this change paves the road to render the options using sphinx, and
will allow us to further annotate the options to include more metadata.

also, a this YAML file can be consumed by applications like dashboard
and Sphinx to consume these metadata in a simpler way.

* use @variable-name@ for substituting the variables in .yaml.in file
* use cmake variable of `mgr_disabled_modules` instead of C macro
  to define `mgr_disabled_modules` in global.yaml.in
* debian/control, ceph.spec.in, win32_deps_build.sh: add python3-yaml
  as build dep
* add y2c.py (short for YAML to C++) to translate .yaml to .cc file
* common/options/*.yaml.in: extract and split options into .yaml.in
  files, the subvars in it is then replaced with CMake variables,
  and copied to the corresponding .yaml files
* include/config-h.in.cmake: remove MGR_DISABLED_MODULES, as it
  is not a CMake variable.

Signed-off-by: Kefu Chai <kchai@redhat.com>