FIO-9592: Add emitting form display change event

[mikekotikov]

Link to Jira Ticket

https://formio.atlassian.net/browse/FIO-9592

Description

What changed?

Added event for form display type change (needed in @formio/react to subscribe and update form json, so to not copy submit button adding/removing logic when switching to Wizard and back)

Why have you chosen this solution?

Use this section to justify your choices

Breaking Changes / Backwards Compatibility

Use this section to describe any potentially breaking changes this PR introduces or any effects this PR might have on backwards compatibility

Dependencies

formio/react/pull/593

How has this PR been tested?

Manually

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