This change adds a basic accounting localization package for Sri Lanka. It includes the chart of accounts, tax groups, taxes, fiscal positions, and local tax reports needed to support VAT and withholding tax filing.

Implement a basic accounting package for Sri Lanka including:

- COA
- Tax groups
- Taxes
- Fiscal Positions
- Tax reports (VAT001, WHT001)

task-4352802

A new reporting module has been added for Sri Lanka, providing basic balance sheet and profit and loss reports. It also includes VAT and withholding tax return data to support local accounting and reporting needs.

Adds basic reporting module for Sri Lanka, including:
- Balance sheet
- Profit & loss

Also adds the account_return_data for VAT and WHT account_reports

task-4352802
CE-https://github.com/odoo/odoo/pull/224917