Playwright locator refactoring

[emilghittasv]

This pull request includes several updates to the playwright_tests module, focusing on improving the handling of locators and ensuring DOM elements are fully loaded before interactions. The most important changes include replacing xpath with Locator for various methods, adding calls to wait_for_dom_to_load, and improving the handling of element interactions.

Improvements to handling locators and DOM loading:

• playwright_tests/core/basepage.py: Replaced xpath with Locator for multiple methods, ensuring that locators are used consistently. Added calls to wait_for_dom_to_load before interacting with elements. [1] [2] [3] [4] [5] [6]
• playwright_tests/core/utilities.py: Updated the upload_file method to use Locator instead of xpath and improved the handling of file uploads.
• playwright_tests/core/utilities.py: Improved the delete_cookies method by replacing wait_for_selector with _wait_for_locator for better locator handling.
• playwright_tests/flows/auth_flows/auth_flow.py: Simplified the __provide_login_credentials_and_submit method by removing redundant checks and directly adding the password and submitting.

[escattone]

Nice changes!