Implement Tax Information Form Screen [Flutter] #48
Description
Build the Tax Information screen with a "Use my profile address" checkbox toggle. When unchecked, show manual input fields: Country of tax residence (dropdown), Address, City, and Postal/zip code. Below, include a Tax Identification section with a Tax ID text input. A "Save details" button submits the form. Also handle the "Country Tax ID" variant which shows Tax ID number, Tax ID type (dropdown), and a second Tax ID number field. The filled state should pre-populate all fields with saved user data.
Acceptance Criteria:
- "Use my profile address" checkbox auto-fills address fields when checked
- Country of tax residence renders as a searchable dropdown
- Address, City, and Postal/zip code are standard text inputs
- Tax Identification section renders Tax ID input field
- Country Tax ID variant shows Tax ID number, Tax ID type dropdown, and secondary Tax ID number field
- Filled state correctly pre-populates all fields with existing data
- "Save details" button is active only when required fields are filled
- "Need Help?" button is visible in the top-right corner