Add some tests for clearpart and related functionality.
Add some tests for clearpart and related functionality.

AdamWill/blivet,vpodzime/blivet,jkonecny12/blivet,rhinstaller/blivet,jkonecny12/blivet,rhinstaller/blivet,vojtechtrefny/blivet,vojtechtrefny/blivet,dwlehman/blivet,AdamWill/blivet,vpodzime/blivet,dwlehman/blivet,rvykydal/blivet,rvykydal/blivet