feature request: add command to stop cmake configure

[zchrissirhcz]

For a medium/large C/C++ project, the cmake configure may take several minutes. And once it is executing, people may realize that he/she forget to change some cache variables, and would like to stop current cmake configure process.

However, with the latest vscode cmake tools, I didn't find a correspoinding command for that. Hope this feature can be added!