Add configuration to decide the amount of slots that will be used in a VM
- This will limit the amount of times that memory can be hotplugged.
- Use memory slots provided by user.
- tests: aling struct
cli: kata-env: Add memory slots info.
- Show the slots to be added to the VM.
```diff
[Hypervisor]
MachineType = "pc"
Version = "QEMU ..."
Path = "/opt/kata/bin/qemu-system-x86_64"
BlockDeviceDriver = "virtio-scsi"
Msize9p = 8192
+ MemorySlots = 10
Debug = false
UseVSock = false
```
Fixes: #751
Signed-off-by: Jose Carlos Venegas Munoz <jose.carlos.venegas.munoz@intel.com>