src/components/__tests__: in FormRegisterCoordinator correct command sequencing and message visibility checks

[maceksimon]

Issue: FormRegisterCoordinator component tests occasionally fail with following problems:

  1) <FormRegisterCoordinator>
       desktop
         validates checkboxes correctly:
     AssertionError: Timed out retrying after 60000ms: Expected to find element: `.q-field__messages`, but never found it. 

...

  2) <FormRegisterCoordinator>
       desktop
         submits form correctly:
     CypressError: Timed out retrying after 5000ms: `cy.wait()` timed out waiting `5000ms` for the 1st request to the route: `registerCoordinator`. No request ever occurred.

Solution:

1. Switch to a more robust check for UI messages using cy.contains to find element by content.
2. Update sequencing of tests, placing the compareRegisterResponseWithStore function to its own .then block (also add nextTick function before checking for store value).