[CMake] Automated versioning

[EmperorYP7]

Description

The version specified in CMake config and the version released by GitHub Actions is not the same and can be really confusing for the clients. We can automate the versioning to coincide the CMake version with the GH version of casbin-cpp through another GitHub Action which should trigger on push to master branch.

[casbin-bot]

@EmperorYP7 @divy9881 @noob20000405 @sheny1xuan

[hsluoyz]

@sheny1xuan

[sheny1xuan]

Good point. But I think it's maybe difficult to do that automatically. Because if we update cmake file atfer a new release, we will generate change in cmakelists.txt. And I can't find a plugin can do that thing. Maybe we can update cmake version with the release rule. This is a very tricky thing. @EmperorYP7

[EmperorYP7]

I'll keep everyone updated once I have a practical approach for this.