Support creation of machine proxies with terraform provider

[nharvey-octopus]

Is your feature request related to a problem? Please describe.

Currently there is no way to create machine proxies via our terraform provider (i.e. Infrastructure | Machine Proxies).

Describe the solution you'd like

Create a method for customers to create machine proxies with our terraform provider.

Describe alternatives you've considered

None other than allowing for direct creation via our terraform provider.

Additional context

Customer opened a ticket with us requesting this feature.