FIO-8264: update validate required

[brendanbond]

Link to Jira Ticket

https://formio.atlassian.net/browse/FIO-8264

Description

Checkbox and selectboxes components that are required will treat false as a falsy value. In other words, if the component (or one of its constituents) is not checked and that component is required, it is not a valid submission. Other components (e.g. container, data map, select, radio buttons) can have false as a value and not be treated as invalid, which was not accounted for in the required validation rule. This PR tightens required validation by:

• not evaluating at all if the component's hidden property is true;
• not considering false a falsy value unless the component is a checkbox or a selectboxes component;
• recursively iterating over object values to ensure nested components don't suffer from the same problem; and
• adding minor updates to the Radio component type.

Breaking Changes / Backwards Compatibility

n/a

Dependencies

n/a

How has this PR been tested?

added tests

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