Add E2E tests to catch errors that happen when non-admin users log to wp-admin

[leonardola]

We need to add E2E tests to prevent errors like #5096 from happening again.

Test case:

• Create non-admin user (Eg: editor)
• Log to wp-admin
• Make sure no errors show up

[jbordonado]

For now, a test was added to the critical flow: https://github.com/Automattic/woocommerce-payments/wiki/Testing-instructions-for-critical-flows#open-admin-area-as-non-admin

Ideally, an E2E test will cover that scenario.

[zmaglica]

This issue impacts E2E, so assigning to Harmony (based on team responsibilities Pc2DNy-3z-p2) @deepakpathania . Please don't hesitate to ping another team lead if you think that the other team might be a better solution.
Assigning as part of Gamma Triage process PcreKM-yM-p2.

[deepakpathania]

Harmony won't be working on adding new E2E tests for product flows, this could potentially go to Gamma or Moltres IMO but not sure.

[vbelolapotkov]

@dwainm sending this one to your team's maintenance backlog. I've assigned the issue to you for this, please take care of adding it to the team board.

Note it has some overlaps with upcoming project, but treat this one as a maintenance issue, please.

[allie500]

Moving to on-hold until PR #10352 is merged.

[allie500]

Picking this one back up as #10352 is merged.