Add Playwright Knowledge base power for Functional Test

[manojaiconf26]

Create new Playwright Knowledge base power for functional testing which would do the following,

1. Create automated UI functional tests for business requirements using Playwright.
2. Guides test structure, Page Object Model, locator strategies, assertions, and CI integration following industry best practices.

Note: I would like to contribute this Power which was built using Kiro Power - Powerbuilder