This commit replaces the `chromedp` library with `playwright-go` for browser automation within the Bilinovel downloader.
Changes include:
* Updated `Bilinovel` struct to manage Playwright browser, context, and page instances.
* Rewrote `initBrowser` and `Close` methods to use Playwright's API for browser lifecycle management.
* Refactored `processContentWithChromedp` to `processContentWithPlaywright`, adapting the logic to use Playwright's page evaluation capabilities.
* Removed unused `context` and `time` imports.
* Added HTML cleanup in `getChapterByPage` to remove `class` attributes from images and `data-k` attributes from all elements, improving content consistency.
