imsm: support RAID 10 with more than 4 drives

imsm: support RAID 10 with more than 4 drives

VROC UEFI driver does not support RAID 10 with more than 4 drives.
Add user prompts if such layout is being created and for R0->R10
reshapes.

Refactor ask() function:
- simplify the code,
- remove dialog reattempts,
- do no pass '?' sign on function calls,
- highlight default option on output.

This patch completes adding support for R10D4+ to IMSM.

Signed-off-by: Mateusz Kusiak <mateusz.kusiak@intel.com>
Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>