Migrate Monitor stage QA selectors to testid

What does this MR do and why?

As per gitlab-org/quality/quality-engineering/team-tasks#1830 (closed) a task of the greater issue gitlab-org/quality/quality-engineering/team-tasks#1735

We are migrating QA selector attributes from data-qa-selector to data-testid. This MR migrates the selectors used in Monitor stage end to end tests.

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