Create a generic Interpolation plugin

[manushak]

Types of changes

• [x] Enhancement (project structure, spelling, grammar, formatting)
• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [x] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [x] I have added tests to cover my changes.
• [x] All new and existing tests passed.

A description of the changes proposed in the Pull Request

• Create a generic interpolation plugin

[manushak]

Hi @manushak thanks for working on this but it doesn't meet the issue spec. The plugin should be generic, by which I mean it should interpolate any arbitrary data that is passed to it in the way described in the acceptance criteria in the ticket, and not require specific parameters such as vcpus-allocated. Please check the ticket description to see how the plugin should work.

@jmcook1186 I've updated, please review

[jmcook1186]

over to @narekhovhannisyan for second review