icon request: Block / Stop

### Describe the Icon

Hey,
I've noticed that there isn't anything for "block". Maybe you should add this.
Should be a smooth circle, and a diagonal line inside. Try to make one with the line pointing top-left, and and another pointing top-right, and another with both.

### Links to Examples

https://www.svgrepo.com/svg/511150/stop-sign
https://www.svgrepo.com/svg/488804/block
https://www.svgrepo.com/svg/505298/block-1

### Additional Information

_No response_

The issue names no files or tests. Start by reviewing the three linked examples and the repository's existing icon conventions, then determine how icon assets are organized and registered. Done means adding the requested block/stop variants while matching the project's established visual and naming conventions.

Scritto dal modello di indicizzazione a partire dal testo della issue.