add fake functions to templates

[jryannel]

E.g. it shall be possible to create fake data for properties, functions, etc.

This shall allow the code generator and the simulation to use fake data

properties:
  - name: value
    type: int
    fake: number:1,10

or

@fake: {number:1,10}
value: int

in the simulation

properties:
  - name: value
    value: 0
    fake: number:1,10

See also https://github.com/brianvoe/gofakeit