Add a note: checkErrorsMode: "onValueChanged" doesn't work for date input fields

[JaneSjs]

• T12662 - Date validation issue
  https://surveyjs.answerdesk.io/internal/ticket/details/T12662#6d3c1d4f-578e-41d2-8106-44362c42d43a
• T18376 - Date type inputs validation
  https://surveyjs.answerdesk.io/internal/ticket/details/T18376

[RomanTsukanov]

We can validate data input fields when they lose focus, but this seems a costly solution. I've added a note about the current behavior to the docs: API Reference | Data Validation help topic.

[JaneSjs]

We handled this issue. Now, date fields are validated on value change: Date Input Fields: Support for Immediate Validation.