Decide on units used in memory-related properties

[marmarek]

Currently there is a big mess. Some of them uses MB (vm.memory, vm.maxmem), some bytes (host.memory_total). And I think I saw KB somewhere too. I vote for MB everywhere.

[marmarek]

Found KB - host.memory_total, despite of comment saying it's in bytes...

[bnvk]

:+1: for MB, it is the most commonly understood data measurement size (based on an unofficial poll).

[woju]

One point to clarify, will that be MB or MiB? In principle I have nothing against any, but I think is important to be precise in the unit symbol. It removes ambiguity.

[alimirjamali]

Related: #7889