FIO-9127 fixed saving an empty value for day component after deleting values

[HannaKurban]

Link to Jira Ticket

https://formio.atlassian.net/browse/FIO-9127

Description

Fixed the issue of saving an empty value for the Day component after deleting values from each of the fields (month, day and year). Previously, the last deleted field was not left empty, so after editing it was impossible to set an empty value for the day component. The issue of setting an empty value for the Day component with the default value has also been fixed

Breaking Changes / Backwards Compatibility

n/a

Dependencies

n/a

How has this PR been tested?

Automated test have been added. Al test pass locally

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