[ccm] add compile-time option to exclude CCM features

[wgtdkp]

This PR adds a CMake option OT_COMM_CCM and feature switch OT_COMM_CONFIG_CCM_ENABLE to turn off Commercial Commissioning Mode support. It has the benefits of increasing code coverage and remove unnecessary dependencies (cn-cbor, COSE-C) when CCM features is not needed.

[codecov-commenter]

Codecov Report

Merging #112 into master will increase coverage by 0.68%. The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master     #112      +/-   ##
==========================================
+ Coverage   61.96%   62.65%   +0.68%     
==========================================
  Files          58       52       -6     
  Lines        5369     4753     -616     
==========================================
- Hits         3327     2978     -349     
+ Misses       2042     1775     -267     

Impacted Files	Coverage Δ
src/library/commissioner_impl.cpp	73.95% <0.00%> (+11.51%)	:arrow_up:
src/library/commissioner_impl.hpp	100.00% <ø> (ø)
src/app/cli/console.cpp	76.92% <0.00%> (-11.54%)	:arrow_down:
src/library/socket.cpp	89.52% <0.00%> (-1.57%)	:arrow_down:
src/library/coap.cpp	71.22% <0.00%> (-0.92%)	:arrow_down:
src/library/commissioner_safe.cpp	62.34% <0.00%> (-0.75%)	:arrow_down:
src/app/commissioner_app.hpp	80.00% <0.00%> (ø)
src/library/commissioner_safe.hpp	100.00% <0.00%> (ø)
include/commissioner/commissioner.hpp	43.75% <0.00%> (ø)
src/library/cbor.hpp
... and 6 more