Implementation of validator for active viewport

[moonyuet]

Changelog Description

This PR is to implement the validator to check whether the render setting is enabling the active viewport for rendering.
Fixes: #165

Additional review information

n/a

Testing notes:

1. Create Render
2. Publish
3. If you lock your viewport through the render setting, it will error out
4. You can repair it
5. Publish successfully
6. Your scene on farm should be rendering in the right camera