refactored Form component code to prevent the exhaustive-deps error for useEffect

[TanyaGashtold]

Link to Jira Ticket

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

Description

What changed?

Moved form instance cleanup to separate hook to prevent exhaustive-deps error.

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Breaking Changes / Backwards Compatibility

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Dependencies

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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