[FEATURE]: Render stages with templates in the render panel

[shapeseas]

User Story

As an experiment designer, I want to be able to build experiments using templates. This will ideally happen in both the YAML editor and through the GUI.

Feature description

Example of using templates in YAML editor: https://github.com/Watts-Lab/deliberation-assets/blob/main/projects/css_lab/ct_topic/ct_topic.treatments.yaml

What would this feature enable?

Using a key part of deliberation-empirica to build experiments

Priority

None

Steps

• Read the treatment file and save each template to local variable
• As the body of the treatment is rendered (introSequences, treatments), when template is referenced, substitute parameters and read from variable.
• Reference to deliberation empirica filling templates: https://github.com/Watts-Lab/deliberation-empirica/blob/main/server/src/preFlight/fillTemplates.js