Quotes: display the tax rate (e.g. 5%) alongside the tax amount in the financial summary

Description: We need the ability to display the tax rate as a percentage alongside the tax dollar amount in the financial summary section of quotes. Today only the tax dollar amount is displayed; the tax rate percentage is not shown.

Use case: While not legally required on quotes in Canada, showing the tax rate is considered best practice and is standard in Canadian quoting workflows. Without it, Canadian MSPs cannot align their quotes with local best practice without manual workarounds.

Proposed solution: Show both the tax rate (e.g. 5%) and the tax dollar amount (e.g. $100.00) in the quote's financial summary.