[Website] Update the set of custom fields on CommonGrants Website

[laurabelinfante]

Summary

Update the list of custom fields based on the outcome of HHS/grants-product-and-delivery#501 and link the custom field catalog to the website navbar and sidebar

Acceptance criteria

• Custom field definitions have been updated
• Custom field catalog is linked from the website's navbar under "Protocol"
• Custom field catalog is linked from the website's sidebar under the "Protocol" section