NO TICKET: rename contact -> participant where appropriate

[jacob-a-brown]

Why

This PR addresses the following problem / context:

• I forgot to update the fields after renaming FieldEventContactAssociation to FieldEventParticipant

How

Implementation summary - the following was changed / added / removed:

• renamed field_contact_role --> participant_role
• renamed mapped contact in FieldEventParticipant table --> participant

Notes

Any special considerations, workarounds, or follow-up work to note?

• Kept the name contact in the sample table

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ All tests successful. No failed tests found.

Files with missing lines	Coverage Δ
db/contact.py	100.00% <ø> (ø)
db/field.py	100.00% <100.00%> (ø)
db/sample.py	100.00% <ø> (ø)
services/sample_helper.py	100.00% <ø> (ø)
tests/conftest.py	100.00% <ø> (ø)

[ksmuczynski]

Does it make sense to add these roles to the role category that exists for Contacts, or is it better to have a separate category for participant_role?

[jacob-a-brown]

At first I thought to do that, but they kind of serve two different purposes. role describes the person (or organization) (e.g. Geologist, Biologist, Technician etc), whereas participant_role describes what role the person had in the field event (Lead, Participant, Observer etc). Trevor Kludt, for example, is a Technician, but during the field events he can be a Lead or a Participant