chore: update PR template to require e2e integration tests for all data plane features (#2129)

Author: igorbernstein2

.github/PULL_REQUEST_TEMPLATE.md

@@ -4,6 +4,7 @@ Thank you for opening a Pull Request! Before submitting your PR, there are a few
 - [ ] Code coverage does not decrease (if any source code was changed)
 - [ ] Appropriate docs were updated (if necessary)
 - [ ] Rollback plan is reviewed and LGTMed
+- [ ] All new data plane features have a completed end to end testing plan
 
 Fixes #<issue_number_goes_here> ☕️