Improve Video block

Improved YouTube Video Embedding: Strip unnecessary elements from embedded YouTube videos, focusing only on the player and controls.

• Example: An embedded video should appear without sidebars showing related videos or ads, just the video and play controls.

Custom Cover Images for Videos: Allow users to select a custom cover image for YouTube videos with a play button overlay.

• Example: A user can upload an image as a thumbnail, which displays a play button in the center, encouraging viewers to click.

Support for Other Video Sources: Allow embedding videos from other platforms like Vimeo or personal hosting services.

• Example: Users can share a video hosted on Vimeo by simply pasting the shareable link.