Summary:
Add some cmake configurations to support cmake install command.
So other cmake based project can depends on yoga by using cmake `find_package` function as follow:
```
find_package(yoga CONFIG REQUIRED)
target_link_libraries(main PRIVATE yoga::yogacore)
```
Resolves https://github.com/facebook/yoga/issues/1057
Pull Request resolved: https://github.com/facebook/yoga/pull/1129
Reviewed By: cortinico
Differential Revision: D40581194
Pulled By: NickGerleman
fbshipit-source-id: 1f67991b31713561cad766d695dae11c6fc78bbf
