Remove most references to old teams config scheme (#22238)

This is a follow up from MST-16, which was commited
in 3858036a4e.

Changes:
* Enrich course teams_configuration from a plain Dict
  to a custom XBlock field that uses the new TeamsConfig
  wrapper class.
* Remove teams_conf property from course, as the previous
  change made it redundant.
* Update teams_enabled implementation.
* Remove teams_max_size field from course, which is
  no longer semantically correct, as max team size
  is now defined on a teamset level.
* Remove teams_topics in order to discourage use of raw
  teams config dict.
* Add convenience properties teamsets and teamsets_by_id
  to course.
* Allow periods and spaces in teamset IDs to avoid breaking
  existing course teams.

Some parts of the code still use the old raw config data
(identifiable by searching "cleaned_data_old_format"),
which we expect to be slowly factored away as we build
new teams features. MST-40 has been created to remove any
remaining references if necessary.

MST-18

* fix: bokchoy test

* fix: remove pdb break

lms/djangoapps/instructor_task/tests/test_tasks_helper.py

@@ -75,6 +75,7 @@ from openedx.core.djangoapps.course_groups.tests.helpers import CohortFactory
 from openedx.core.djangoapps.credit.tests.factories import CreditCourseFactory
 from openedx.core.djangoapps.user_api.partition_schemes import RandomUserPartitionScheme
 from openedx.core.djangoapps.util.testing import ContentGroupTestCase, TestConditionalContent
+from openedx.core.lib.teams_config import TeamsConfig
 from shoppingcart.models import (
     Coupon,
     CourseRegistrationCode,
@@ -96,6 +97,12 @@ from ..models import ReportStore
 from ..tasks_helper.utils import UPDATE_STATUS_FAILED, UPDATE_STATUS_SUCCEEDED
 
 
+_TEAMS_CONFIG = TeamsConfig({
+    'max_size': 2,
+    'topics': [{'id': 'topic', 'name': 'Topic', 'description': 'A Topic'}],
+})
+
+
 class InstructorGradeReportTestCase(TestReportMixin, InstructorTaskCourseTestCase):
     """ Base class for grade report tests. """
 
@@ -403,9 +410,7 @@ class TestInstructorGradeReport(InstructorGradeReportTestCase):
             course = CourseFactory.create(
                 cohort_config={'cohorted': True, 'auto_cohort': True, 'auto_cohort_groups': ['cohort 1', 'cohort 2']},
                 user_partitions=[experiment_partition],
-                teams_configuration={
-                    'max_size': 2, 'topics': [{'topic-id': 'topic', 'name': 'Topic', 'description': 'A Topic'}]
-                },
+                teams_configuration=_TEAMS_CONFIG,
             )
         _ = CreditCourseFactory(course_key=course.id)
 
@@ -451,9 +456,7 @@ class TestTeamGradeReport(InstructorGradeReportTestCase):
 
     def setUp(self):
         super(TestTeamGradeReport, self).setUp()
-        self.course = CourseFactory.create(teams_configuration={
-            'max_size': 2, 'topics': [{'topic-id': 'topic', 'name': 'Topic', 'description': 'A Topic'}]
-        })
+        self.course = CourseFactory.create(teams_configuration=_TEAMS_CONFIG)
         self.student1 = UserFactory.create()
         CourseEnrollment.enroll(self.student1, self.course.id)
         self.student2 = UserFactory.create()
@@ -1547,9 +1550,7 @@ class TestTeamStudentReport(TestReportMixin, InstructorTaskCourseTestCase):
 
     def setUp(self):
         super(TestTeamStudentReport, self).setUp()
-        self.course = CourseFactory.create(teams_configuration={
-            'max_size': 2, 'topics': [{'topic-id': 'topic', 'name': 'Topic', 'description': 'A Topic'}]
-        })
+        self.course = CourseFactory.create(teams_configuration=_TEAMS_CONFIG)
         self.student1 = UserFactory.create()
         CourseEnrollment.enroll(self.student1, self.course.id)
         self.student2 = UserFactory.create()