Only allow some fields to be added multiple times

Problem/Motivation

Currently every log/asset field can be added multiple times to the template. There are two features this supports:
- If the entity field is multi-value, then multiple template fields make it easy to provide multiple values. Useful for log quantities and asset references.
- For single-value entity fields, this allows you to "combine" multiple template questions to a single entity field value. This is useful for the log name (Create a hidden prefix, with a user-completed suffix) and for the log notes (ask separate questions for values to include in the notes).

For other fields, this does not make sense and creates validation errors:
- Status
- Land type
- Timestamp
- Boolean fields ("is_movement")

Steps to reproduce

N/A

Proposed resolution

Only allow some single-value entity fields of special types to be added multiple times (text, textarea, - are there others?)

Remaining tasks

Implement

User interface changes

Some field options will be removed once already added to the template.

API changes

None

Data model changes

None