cypress: budgets -> Switch -> can switch between budgets flaky

[morremeyer]

The budgets -> Switch -> can switch between budgets test is flaky, but this is not triggered often.

Check Cypress Cloud for an example of a fail.

This happens when, on budget creation, {enter} is pressed, but the check for the loding icon is successful before it even appears.

In that case, the loading of the created budget happens after the click on "Switch budget" and the budget selection view is never loaded.

Potential fix: Update awaitLoading to first expect the loading icon to exist and then to not exist anymore.