FIO-9350 Wizard: Show form-level errors after failed submission on subsequent form interaction when current page has no errors

[blakekrammes]

Link to Jira Ticket

https://formio.atlassian.net/browse/FIO-9350

Description

What changed?

• Updated setPage() to display form errors if the form has failed to submit. setPage() is called when a user clicks
  directly on a Wizard nav link/button, but onChange() is not (this bug was fixed for onChange() by FIO-9360).
• Updated nextPage() to check for failed submission; if there has been, display all the form errors. This is necessary for when a user clicks the "next" button without having resolved the error for that page. It causes validation to trigger for the current page only and wipes the other form errors.
• Updated get errors() a.k.a. this.errors to grab the form-level errors if the form previously failed to submit. While this.showErrors() displayed the errors correctly, while testing I discovered that the errors were wiped incorrectly from the Wizard instance in this scenario and this.errors fell back to only returning errors for the current page.

Why have you chosen this solution?

• Same concept/logic as FIO-9360, but applied to a couple more places.
  Basically, we check if the form has previously submitted (indicating a failed submission). If it has, we show all the form
  errors on every page until they are resolved individually on each page, as opposed to only validating the current page.
  FIO-9360 did this onChange(), but not for setPage() and nextPage().

Breaking Changes / Backwards Compatibility

n/a

Dependencies

n/a

How has this PR been tested?

Automated and manual. I de-duped up one of commonly-used helper functions in the Wizard tests and made it a global helper at the top of the Wizard tests. I also updated the async syntax for a flaky test to aid in potential future debugging.

Checklist:

• I have completed the above PR template
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (if applicable)
• My changes generate no new warnings
• My changes include tests that prove my fix is effective (or that my feature works as intended)
• New and existing unit/integration tests pass locally with my changes
• Any dependent changes have corresponding PRs that are listed above