ENG-2790 Set Default Tabs for Integrations Dialog

[agiron123]

Describe your changes and why you are making these changes

This PR fixes JavaScript console errors related to integrations dialogs not having default tab values set.

It also fixes error messages related to using null instead of empty string when there is no value to be rendered in a text field (react prefers empty strings in our case)

Related issue number (if any)

ENG-2790

Loom demo (if any)

https://www.loom.com/share/a47669ed643f49a18dd31ea24d08a044

Checklist before requesting a review

• I have created a descriptive PR title. The PR title should complete the sentence "This PR...".
• I have performed a self-review of my code.
• 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)

[likawind]