Ability to set hotpluggable resources

[miberecz]

Is your feature request related to a problem? Please describe.
No

Describe the solution you'd like
Ability to set each hotplug resource via terraform

In the GUI, there it is:

It can be modified already via the API:
https://pve.proxmox.com/pve-docs/api-viewer/#/nodes/{node}/qemu/{vmid}/config
"hotplug"

Describe alternatives you've considered
Can be done via an API call as a workaround, but would be nice to have all settings in one place in a .tf file

[bpg]

Thanks @miberecz! Also related to #538