[Request] Add icons to bookmarks links

Hi,

instead of the standard svg icon beside the link 

I would like to have (as other users) the ability to change it to a local or remote icon file.

That would help a lot as an icon is **more speaking** than a text.

| Before: | After: |
| ----------- | ----------- |
|  |  |

**Suggestion of formating**
```yaml
Collection:
- Bucket:
- url: https://example.com/
- ico: example.png
```
or (google favicon api)
```yaml
Collection:
- Bucket:
- url: https://example.com/
- ico: https://www.google.com/s2/favicons?domain=${domain}&sz=${size}
```
or (base64)
```yaml
Collection:
- Bucket:
- url: https://example.com/
- ico: data:image/png;base64,...
```

Anything that works is welcome.

// **update**

Here https://github.com/maximtrp/tab a lite similar project by @maximtrp with icons integration capability.

The payload names no files or tests; start by locating the bookmark-link rendering entry point and the YAML configuration handling, then compare the before and after screenshots. Done means bookmark entries can specify local or remote icons, including the formats shown in the issue, and the configured icon renders beside the link.

Written by the indexing model from the issue text.