feat: Extend service template

[sebastianczech]

Description

PR delivers changes from second bullet in #48:

• refactored template for service.go
• changes in template for location.go (prepare to use uuid)
• extension of example used to communicate with firewall
• fixes in security policy rule spec file for problems found while testing with firewall
• improvements in functions used in templates rendering

Motivation and Context

#48

How Has This Been Tested?

Code was tested by unit tests and by generating pango and configuring firewall.

Types of changes

• New feature (non-breaking change which adds functionality)

Checklist

• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes if appropriate.
• All new and existing tests passed.