Delete old wagtail page models

[Kyle-Verhoog]

These were either never used or no longer used with the migration to an
SPA.

Resolves #202

[Kyle-Verhoog]

This needs migrations still.

[Kyle-Verhoog]

Hmm the migration doesn't seem to work:

~/d/crossroads ❮❮❮ n dc exec app python manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, chat, church, comments, contenttypes, polls, prayer, sessions, taggit, wagtailadmin, wagtailcore, wagtaildocs, wagtailembeds, wagtailforms, wagtailimages, wagtailmedia, wagtailredirects, wagtailsearch, wagtailusers
Running migrations:
  Applying church.0025_auto_20210602_0022...Traceback (most recent call last):
  File "/usr/local/lib/python3.9/site-packages/django/db/backends/utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "/usr/local/lib/python3.9/site-packages/django/db/backends/sqlite3/base.py", line 413, in execute
    return Database.Cursor.execute(self, query, params)
sqlite3.OperationalError: near ")": syntax error

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/app/manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/usr/local/lib/python3.9/site-packages/django/core/management/__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "/usr/local/lib/python3.9/site-packages/django/core/management/__init__.py", line 395, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/usr/local/lib/python3.9/site-packages/django/core/management/base.py", line 330, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/usr/local/lib/python3.9/site-packages/django/core/management/base.py", line 371, in execute
    output = self.handle(*args, **options)
  File "/usr/local/lib/python3.9/site-packages/django/core/management/base.py", line 85, in wrapped
    res = handle_func(*args, **kwargs)
  File "/usr/local/lib/python3.9/site-packages/django/core/management/commands/migrate.py", line 243, in handle
    post_migrate_state = executor.migrate(
  File "/usr/local/lib/python3.9/site-packages/django/db/migrations/executor.py", line 117, in migrate
    state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
  File "/usr/local/lib/python3.9/site-packages/django/db/migrations/executor.py", line 147, in _migrate_all_forwards
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
  File "/usr/local/lib/python3.9/site-packages/django/db/migrations/executor.py", line 227, in apply_migration
    state = migration.apply(state, schema_editor)
  File "/usr/local/lib/python3.9/site-packages/django/db/migrations/migration.py", line 124, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "/usr/local/lib/python3.9/site-packages/django/db/migrations/operations/fields.py", line 166, in database_forwards
    schema_editor.remove_field(from_model, from_model._meta.get_field(self.name))
  File "/usr/local/lib/python3.9/site-packages/django/db/backends/sqlite3/schema.py", line 346, in remove_field
    self._remake_table(model, delete_field=field)
  File "/usr/local/lib/python3.9/site-packages/django/db/backends/sqlite3/schema.py", line 283, in _remake_table
    self.execute("INSERT INTO %s (%s) SELECT %s FROM %s" % (
  File "/usr/local/lib/python3.9/site-packages/django/db/backends/base/schema.py", line 142, in execute
    cursor.execute(sql, params)
  File "/usr/local/lib/python3.9/site-packages/django/db/backends/utils.py", line 98, in execute
    return super().execute(sql, params)
  File "/usr/local/lib/python3.9/site-packages/django/db/backends/utils.py", line 66, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "/usr/local/lib/python3.9/site-packages/django/db/backends/utils.py", line 75, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "/usr/local/lib/python3.9/site-packages/django/db/backends/utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "/usr/local/lib/python3.9/site-packages/django/db/utils.py", line 90, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "/usr/local/lib/python3.9/site-packages/django/db/backends/utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "/usr/local/lib/python3.9/site-packages/django/db/backends/sqlite3/base.py", line 413, in execute
    return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: near ")": syntax error

this needs to be triaged before this PR is merged 😕