Description of problem:
Currently when choosing memory amount in the GUI console, the memory is applied to `vmi.spec.domain.resources.requests[memory]`.

This field is NOT meant to reflect the amount of memory allocated to the guest, but instead the amount of memory allocated to the virt-launcher pod (which includes virtualization infrastructure overhead in addition to the guest memory).

When users set a memory amount for VMs/VMIs, they mean to set `vmi.spec.domain.memory.guest`, which specifies the amount of memory the guest could use.

Version-Release number of selected component (if applicable):

How reproducible:
100%

Steps to Reproduce:
1. Define a VM with certain amount of memory
2. See that for this vmi `vmi.spec.domain.resources.requests[memory]` is being set with the specified amount.
3.

Actual results:
When defining a VMI with a memory amount, `vmi.spec.domain.resources.requests[memory]` field is being set.

Expected results:
When defining a VMI with a memory amount, `vmi.spec.domain.memory.guest` should be set.
`vmi.spec.domain.resources.requests[memory]` should stay empty unless the user had explicitly asked to populate it.