Allow for embedded data URLs as icons.

### Is your feature request related to a problem?

The problem is some tools have their images as data URLs so there is no "Logo" / Favicon to access.

### Describe the solution you'd like

It would be nice to allow for data:image/svg+xml... Like the below example from Portainer.

data:image/svg+xml;base64,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

### Describe alternatives that you've considered

Manual decoding this then saving as file THEN upload etc. ... is quite some work.

### Additional context

I noticed more web application use likewise embedded images as it saves roundtrip times fetching data.
So it creates a lot faster responding websites.

Start by locating the existing icon or logo input and the code that validates, stores, or renders image URLs. Use the provided Portainer data URL as a reproduction case and check the current icon-related tests, if present. Done means a supported data:image/svg+xml URL can be used as an icon without manual decoding or file upload.

Written by the indexing model from the issue text.