Add support for Infrastructure Architecture as Code and Deployment Diagrams generation

[SlavaVedernikov]

Context

At the moment AaC DSL supports only Application Architecture

Requirements

Add support for Infrastructure Architecture as Code, so that it can be described independently of Application Architecture as Code, but referencing its Structures (i.e. similar to Business Process as Code DSL, which is independent of Application Architecture as Code, but references Interfaces in Activity Flows)

Infrastructure Architecture as Code can then be used to generate C4-PlantUML Deployment Diagrams.

See Issue-62 in Documentation for more details.