Added script msg preview feature.

[Djcarrillo6]

Fixes # (issue)

• Skills assessment prompt-2 feature request

Description

Added a message preview that fully renders all custom fields from a custom script. If you upload a list of contacts with custom fields, all fields should fully render into your designed message preview that is rendered through the browser Alert API pop-up. The message is viewable from the create campaign administrator view.

When you click into the input form of the script, there is now a third button that is labeled "Preview" as shown in the circled button of image below:

Checklist:

• [ ] I have manually tested my changes on desktop and mobile
• [ ] The test suite passes locally with my changes
• [ ] If my change is a UI change, I have attached a screenshot to the description section of this pull request
• [ ] My change is 300 lines of code or less, or has a documented reason in the description why it’s longer
• [ ] I have made any necessary changes to the documentation
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] My PR is labeled [WIP] if it is in progress

[Djcarrillo6]

@psbarnacle I could only select you(didn't see the username of the others) as a PR reviewer you from this comment box context. I don't know if I have the ability to request PR reviewers from the look of my current UI: