Enable e2e tests using emulators for cloud providers [ aws, gcp, azure ]

[anveshreddy18]

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What this PR does / why we need it:

This PR enables e2e tests ( cluster based tests ) to be run with the emulators of 3 major cloud providers i.e AWS, GCP, AZURE. And of course can be run with the real infra as well. The reason for using emulators is to reduce the cost of using real infra every time a PR is raised because with the enablement of e2e tests with this PR, these tests will be run as prow job for every PR.

This PR also partially updates the outdated charts to reflect the changes made to the backup-restore over the years. This will help the users with setting up backup-restore effortlessly and also helps the developers with testing etcdbr standalone

Which issue(s) this PR fixes: Fixes #722

Special notes for your reviewer:

Release note:

Enable e2e tests with cloud provider emulators and update helm charts for latest version of `etcdbr` to be used with etcd-wrapper