Allow explicit requests for extended partitions. (#891861)
Allow explicit requests for extended partitions. (#891861)

As of now this only works if you process the actions immediately after
allocating the empty extended.

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