Convert JobUpdateTemplate class to pydantic model

[helen-m-lin]

Is your feature request related to a problem? Please describe.
As a developer, I want all config classes to be consistent and use pydantic models when possible. The JobUpdateTemplate class currently configures and creates the job upload template using a static method. This can be refactored to be a pydantic model and can also ease future conversion to form-based templating.

Describe the solution you'd like
Refactor /configs/job_upload_template.py as a pydantic model.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.