Add appropriate workflow count to our connected notification cards and details page

[kenxu95]

@likawind for backend review. @agiron123 to look at frontend.

Describe your changes and why you are making these changes

See the demo. This adds the appropriate workflow counts and frontend alterations to the connected email and slack resources.

Related issue number (if any)

ENG-2893 Also fixes ENG-2949

Loom demo (if any)

https://www.loom.com/share/5a96f8a72146441ea18eadac8ec08306

Checklist before requesting a review

• [x] I have created a descriptive PR title. The PR title should complete the sentence "This PR...".
• [x] I have performed a self-review of my code.
• [x] I have included a small demo of the changes. For the UI, this would be a screenshot or a Loom video.
• [ ] If this is a new feature, I have added unit tests and integration tests.
• [ ] I have run the integration tests locally and they are passing.
• [ ] I have run the linter script locally (See python3 scripts/run_linters.py -h for usage).
• [ ] All features on the UI continue to work correctly.
• [ ] Added one of the following CI labels:
  • run_integration_test: Runs integration tests
  • skip_integration_test: Skips integration tests (Should be used when changes are ONLY documentation/UI)