Support for Taiwan holidays

[takeshiyu]

Contributing a new country ?

• [x] Have you checked to ensure there aren't other open Pull Requests for the same country?

1. Create a new class in the Countries directory. It should extend the Country class.
2. Add a test for the new country in the tests directory.
3. Run the tests so a snapshot gets created.
4. Verify the result in the newly created snapshot is correct.

Changes

1. Added a new Taiwan class in the Holidays directory.
2. Implemented holiday calculations specific to Taiwan, including both fixed-date holidays and those that require lunar calendar calculations.
3. Used the ext-intl extension and IntlDateFormatter for accurate lunar calendar calculations, ensuring that holidays based on the lunar calendar are correctly determined.

Additional Notes

1. The ext-intl extension is required for this addition. It is referenced in the composer.json file.

References

1. https://publicholidays.tw/2024-dates/

[Nielsvanpach]

Thanks!