CLD-5783 Implement rolling upgrade tests (#27842)

* Make server.prepare idempotent, don't cleanup containers on server.start
* Implement rolling upgrade E2E tests
* Apply Akis' suggestions from code review
* Apply Saturn's suggestions from review
* Communicate RollingRelease on GHA and test automation results channel
* Implement E2E test case versioning for rolling release tests

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Co-authored-by: Mattermost Build <build@mattermost.com>
Co-authored-by: Akis Maziotis <akis.maziotis@mattermost.com>

e2e-tests/cypress/save_report.js

@@ -23,6 +23,7 @@
  *      - TM4J_FOLDER_ID=[folder_id], e.g. 847997
  *   For sending hooks to Mattermost channels
  *      - FULL_REPORT, WEBHOOK_URL and DIAGNOSTIC_WEBHOOK_URL
+ *      - If AUTOMATION_DASHBOARD_FRONTEND_URL is set, a link to the corresponding cycle will be included in the report message
  *   Test type
  *      - TYPE=[type]; valid values: "PR", "RELEASE", "MASTER", "MASTER_UNSTABLE", "CLOUD", "CLOUD_UNSTABLE", "NONE"
  *   Server type