refactor(date-time-input): New parser and date parts logic

[rkaraivanov]

• Refactored date-time-input to use a new datetime mask parser
• Created date-part components to handle individual date/time parts
• Updated validators and tests accordingly
• Removed old date-util files
• Code cleanup and minor improvements in related components
• Updated i18n controller for better localization support
• Fixed an issue with style parts in the date-time-input component

Closes #2072

[Copilot]

Pull request overview

This PR refactors the date-time-input component by replacing the previous date utility classes with a new parser architecture and dedicated date-part components.

Changes:

• Introduced a new DateTimeMaskParser class for handling date/time format parsing and validation
• Created individual date-part classes to encapsulate validation and spin logic for each date/time component
• Migrated validation and formatting logic from the old DateTimeUtil to the new architecture
• Updated i18n controller for better localization support and centralized date formatting

Reviewed changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/index.ts	Updated exports to reference new date-part module
src/components/mask-input/mask-input.ts	Refactored to use new _isEmptyMask getter
src/components/mask-input/mask-input-base.ts	Added _isEmptyMask getter for cleaner empty mask checks
src/components/date-time-input/validators.ts	Updated validators to use new helper functions and public methods
src/components/date-time-input/datetime-mask-parser.ts	New parser class for date/time mask handling
src/components/date-time-input/datetime-mask-parser.spec.ts	Tests for the new datetime mask parser
src/components/date-time-input/date-util.ts	Removed old date utility class
src/components/date-time-input/date-util.spec.ts	Removed old date utility tests
src/components/date-time-input/date-time-input.ts	Refactored to use new parser and date-part architecture
src/components/date-time-input/date-time-input.spec.ts	Updated tests to work with new architecture and added i18n tests
src/components/date-time-input/date-part.ts	New date-part classes for encapsulating validation and spin logic
src/components/date-time-input/date-part.spec.ts	Tests for date-part classes
src/components/date-range-picker/date-range-picker.utils.spec.ts	Updated to use new i18n formatting functions
src/components/date-range-picker/date-range-picker.ts	Updated to use new i18n formatting functions
src/components/date-picker/date-picker.ts	Updated to use new i18n formatting functions
src/components/common/i18n/i18n-controller.ts	Added date formatting utilities and fixed resource change callback binding
src/components/calendar/helpers.ts	Enhanced type safety for isValidDate and added date comparison helpers