fix(ACI): Increase test coverage and fix inconsistencies

[ceorourke]

Follow up to #109926 (comment) to increase test coverage for the issue alert rule POST endpoint backwards compatibility. Adding this test coverage uncovered a few inconsistencies that are fixed in this PR as well.

Note that I will need to rebase off of #110807 once it is merged.

[linear-code]

ISWF-2212 Beef up old v new test coverage for Issue alert POST backwards compatibility

[github-actions]

Backend Test Failures

Failures on b759074 in this run:

tests/sentry/api/serializers/test_rule.py::WorkflowRuleSerializerTest::test_every_condition — log

tests/sentry/api/serializers/test_rule.py:542: in test_every_condition
    self.assert_equal_serializers(issue_alert)
tests/sentry/api/serializers/test_rule.py:160: in assert_equal_serializers
    assert condition in workflow_conditions
E   AssertionError: assert {'comparisonType': 'count', 'id': 'sentry.rules.conditions.event_frequency.EventFrequencyPercentCondition', 'interval': '1h', 'name': 'The issue affects more than 50 percent of sessions in 1h', ...} in [{'id': 'sentry.rules.conditions.high_priority_issue.ExistingHighPriorityIssueCondition', 'name': 'Sentry marks an exi...frequency.EventFrequencyCondition', 'interval': '1h', 'name': 'The issue is seen more than 100 times in 1h', ...}, ...]

tests/sentry/api/serializers/test_rule.py::WorkflowRuleSerializerTest::test_email_action_simple — log

tests/sentry/api/serializers/test_rule.py:564: in test_email_action_simple
    self.assert_equal_serializers(rule)
tests/sentry/api/serializers/test_rule.py:171: in assert_equal_serializers
    assert action in workflow_actions
E   AssertionError: assert {'id': 'sentry.mail.actions.NotifyEmailAction', 'name': 'Send a notification to Member and if none can be found then send a notification to ActiveMembers', 'targetIdentifier': '62', 'targetType': 'Member'} in [{'fallthroughType': 'ActiveMembers', 'id': 'sentry.mail.actions.NotifyEmailAction', 'name': 'Send a notification to M...o Team and if none can be found then send a notification to ActiveMembers', 'targetIdentifier': 4557805100335104, ...}]