[ADD] hr_payroll_tds: Introduced Tax Declaration Sub-menu

[siha-odoo]

With this commit

• Added a Tax Declaration sub-menu under the Contracts menu, allowing users to define new TDS declarations.

• Introduced a "Generate Declarations" button in the TDS declaration form, opening a wizard for selecting employees.

• Implemented four selection modes for employee filtering:

  • By Employee
  • By Department
  • By Job Position
  • By Salary Structure

• Based on the selected mode, the relevant field (e.g., list of departments for "By Department") is dynamically displayed.

• Employees are filtered according to the selected criteria, ensuring that only those with valid contracts are included.

• TDS Declaration Form Enhancements:

  • A stat button now displays the count of generated tax declarations.
  • Clicking the stat button opens a list view of the generated declarations.
  • Clicking on a specific declaration opens its form view for detailed review.

• TDS Calculation & Deductions:

  • The Tax Declaration tab in the form now computes TDS based on the New Tax Regime and an employee’s total income.
  • Added an "Other Deductions" tab to manage additional deductions.

• Integration with Employee Form:

  • A TDS Declaration stat button is now available on the Employee form.
  • Clicking it opens a list of TDS declarations related to the selected employee.

[robodoo]