Add option to specify user to run sanity tests with in GHA (#2806)

![2023-03-15-17-51-55](https://user-images.githubusercontent.com/14259816/225307537-91e3754e-c08a-4457-9482-999cc9d5b084.png)


---

#### Does this PR need a docs update or release note?

- [ ] ✅ Yes, it's included
- [ ] 🕐 Yes, but in a later PR
- [x] ⛔ No

#### Type of change

<!--- Please check the type of change your PR introduces: --->
- [ ] 🌻 Feature
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Test
- [x] 💻 CI/Deployment
- [ ] 🧹 Tech Debt/Cleanup

#### Issue(s)

<!-- Can reference multiple issues. Use one of the following "magic words" - "closes, fixes" to auto-close the Github issue. -->
* #<issue>

#### Test Plan

<!-- How will this be tested prior to merging.-->
- [x] 💪 Manual
- [ ] ⚡ Unit test
- [ ] 💚 E2E

.github/workflows/sanity-test.yaml

@@ -4,6 +4,9 @@ on:
     branches:
       - main
   workflow_dispatch:
+    inputs:
+      user:
+        description: 'User to run sanity test on'
 
 permissions:
   # required to retrieve AWS credentials
@@ -24,7 +27,7 @@ jobs:
       AZURE_CLIENT_ID: ${{ secrets.CLIENT_ID }}
       AZURE_CLIENT_SECRET: ${{ secrets.CLIENT_SECRET }}
       AZURE_TENANT_ID: ${{ secrets.TENANT_ID }}
-      CORSO_M365_TEST_USER_ID: ${{ secrets.CORSO_M365_TEST_USER_ID }}
+      CORSO_M365_TEST_USER_ID: ${{ github.event.inputs.user != '' && github.event.inputs.user || secrets.CORSO_M365_TEST_USER_ID }}
       CORSO_PASSPHRASE: ${{ secrets.INTEGRATION_TEST_CORSO_PASSPHRASE }}
       TEST_RESULT: "test_results"
       CORSO_BUCKET: ${{ secrets.CI_TESTS_S3_BUCKET }}