This adds MBR support and vfat to rootio

[thebsdbox]

Description

This PR, extends CPR to support MBR type partitions instead of the default GPT

Why is this needed

VMware requires it's installation disk to be in this format.

Fixes: #

How Has This Been Tested?

How are existing users impacted? What migration steps/scripts do we need?

Hidden behind an MBR environment variable, users wont see it by default.

Checklist:

I have:

• [x] updated the documentation and/or roadmap (if required)
• [x] added unit or e2e tests
• [ ] provided instructions on how to upgrade

dan@code:~/go/src/github.com/tinkerbell/hub/actions/rootio/v1$ sudo TEST=y MBR=true JSON_FILE=./test/mbr.json ./v1 partition
Successfully Opened test data
Succesfully parsed the MetaData, Found [1] Disks
ROOTIO - Disk Manager
------------------------
Parsing MetaData
INFO[0000] Examining disk [/dev/sdb]                    
INFO[0000] Disk Size [16384MB]                          
INFO[0000] Found [4] partitions                         
INFO[0003] Wrote [1073741824] bytes to [/dev/sdb]       
INFO[0003] Flushing writes to new partition             
INFO[0004] Wiping                                       
INFO[0004] Partitioning                                 
INFO[0004] New Partition Name=FAT32_ACTIVE Start=2048 Size=33552384 
INFO[0004] Flushing writes to new partition             

dan@code:~/go/src/github.com/tinkerbell/hub/actions/rootio/v1$ sudo fdisk -l /dev/sdb
Disk /dev/sdb: 16 GiB, 17179869184 bytes, 33554432 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x00000000

Device     Boot Start      End  Sectors Size Id Type
/dev/sdb1  *     2048 33554431 33552384  16G  c W95 FAT32 (LBA)