fix: ensure `isReadonly` applies to all non-literal date segments (#7969)
* fix: force data-readonly when datefield is readonly
* chore: simplify isEditable
* adding tests
* update based on expectations
* fix formatting
* Apply suggestion from @snowystinger
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Co-authored-by: Robert Snow <rsnow@adobe.com>
Co-authored-by: Robert Snow <snowystinger@gmail.com>