SMS biweekly skinny volunteer digest for supervisors

[Zrrrpy]

part of epic #1017, dependent on #1785, #1791, #1780, #1781, #1782

AS a supervisor,
I WANT to receive an SMS notification every two weeks telling me which of my active volunteer assignments have not logged a case_contact in 14 days or more,
SO THAT I know which of my volunteers to follow up with.

How it works now

Currently, supervisors receive a weekly digest email on Monday containing an overview of all volunteer activity for the past week. (see #23)

How it should work

Supervisors should additionally (if they choose to in their preferences, see #1016) receive an SMS notification once every two weeks informing them of which of their assigned volunteers haven't logged any case_contacts in the past two weeks.

IF a supervisor is actively assigned to any volunteers with active case assignments who haven't logged a case_contact in two weeks or more,
THEN they receive an SMS notification.

Acceptance criteria

• When the above conditions are met, a supervisor receives an SMS notification.
• The notification is sent in three separate messages:
• The first should read something like this:
  The following volunteers haven't logged a case contact in two weeks or more:
• The second message should be a list of the display_names of the supervisor's volunteers who haven't logged a case_contact in two weeks or more
• The third message should read something like:
  Please follow up with these volunteers to ensure they are tracking time spent with their youth and team.

This issue has been open without changes for a long time! What's up?

[compwron]

Closing for now due to lack of demand