FIO-10545: update @formio/js peerDependencies

[Maria-Golomb]

Link to Jira Ticket

https://formio.atlassian.net/browse/FIO-10545

Description

Updated @formio/js to ^5.0.0 (stable) in peerDependencies and devDependencies.
Added autotests.

Vitest Testing Framework was chosen because:

The project already uses Vite.

Vitest works with existing Vite setup.
Vitest uses same vite.config.ts for build and test.
Handles ES modules without complex configuration
TypeScript built-in
Built specifically for Vue/Vite projects
Has Jest-compatible API (familiar syntax)

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

Use this section to list any dependent changes/PRs in other Form.io modules

How has this PR been tested?

Use this section to describe how you tested your changes; if you haven't included automated tests, justify your reasoning

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

[francoisauclair911]

@Maria-Golomb I'm actually not sure that the failing test using @ungap/structured-clone were only in testing. I've had bugs in normal codebase also
#95 is my attempt for a fix.