fixed inconsistent usages of memory units (MB/MiB and GB/GiB)

[daFritz84]

partly fixes #126

Consolidated memory units to MiB and GiB. Now output from vagrant and ovirt should match up (i.e. 4096 MiB is shown as 4096MB at the web dashboard)

Tested OK with ovirt 4.4.2.6-1.el8 on Ubuntu 20.04 WSL on Windows 20H2

Log:

❯ vagrant up
Bringing machine 'default' up with 'ovirt4' provider...
==> default: Creating VM with the following settings...
==> default:  -- Name:          backup-monitoring
==> default:  -- Cluster:       Intel_Cluster
==> default:  -- Template:      centos-8-stream
==> default:  -- Console Type:  vnc
==> default:  -- BIOS Serial:
==> default:  -- Optimized For:
==> default:  -- Description:
==> default:  -- Comment:
==> default:  -- Memory:
==> default:  ---- Memory:      4096 MiB
==> default:  ---- Maximum:     4096 MiB
==> default:  ---- Guaranteed:  4096 MiB
==> default:  -- Cpu:
==> default:  ---- Cores:       2
==> default:  ---- Sockets:     1
==> default:  ---- Threads:     2
==> default:  -- Cloud-Init:    true
==> default: Waiting for VM to become "ready" to start...
==> default: Starting VM.
==> default: Waiting for VM to get an IP address...
==> default: Got IP: 10.20.182.6
==> default: Got IP: 10.20.182.6
==> default: Got IP: 10.20.182.6
==> default: Got IP: 10.20.182.6
==> default: Got IP: 10.20.182.6
==> default: Got IP: 10.20.182.6
==> default: Got IP: 10.20.182.6
==> default: Got IP: 10.20.182.6
==> default: Machine is booted and ready for use!
    default:
    default: Vagrant insecure key detected. Vagrant will automatically replace
    default: this with a newly generated keypair for better security.
    default:
    default: Inserting generated public key within guest...
    default: Removing insecure key from the guest if it's present...
    default: Key inserted! Disconnecting and reconnecting using new SSH key...
==> default: Rsyncing folder: /mnt/c/Users/SES/Source/ansible-backup-monitoring/vagrant/ => /vagrant
==> default: Setting hostname...