Icons integration

[Simbiat]

As mentioned in #8029 I was thinking of adding a PHP class to https://github.com/Simbiat/DeviceDetectorIcons and... I just did. While the collection of icons is still incomplete (519 brands and all bots still pending), thanks to fallback logic it probably can be used much more easily now, so creating this "issue" to discuss potential deeper integration.

Firstly, I am not talking about replacement of https://github.com/matomo-org/matomo-icons, since at least that one has a bunch of other icons. My collection is specifically icons for clients/devices/bots, so essentially user agents themselves. Here's what I am thinking:

1. Integrate it into DeviceDetector: add icon field to respective entities inside of it or maybe a separate "block" called icons, which would be populated by the results of my class only if the class exists on the system
2. Add my class as recommended in the composer.json for DeviceDetector
3. Update Matomo's code itself to search for icons in DeviceDetector object, and if not found - fallback to existing logic from matomo-icons

If this kind of integration is done, I would prefer to move the repo to Matomo as well for extra visibility (both for more downloads and more potential hands maintaining it besides just me). I will continue maintaining it, of course, at least till I complete all currently missing brands and bots, and most likely after that as well. I am also ready to do all necessary PRs for integration itself, of course.

Let me now, what you guys think.