PR Checklist:

• [ ✓ ] I have tested this extensively and it does not break any existing behavior.
• [ ✓ ] I have added/updated examples and tests for any new behavior.
• [ ✓ ] If this is a significant change, an issue has already been created where the problem / solution was discussed: N/A

PR Description:

Added rounded corners for Pie Chart

Added Feature:

This PR is for PieChartRenderer.

PR has to be merged:

So that users can customise PieChart corners according to their requirements.