Asset Library author link, description popup size and UX details

[ckaiser]

I noticed that the asset library had some weird UI stuff, especially LinkButtons that didn't do anything when clicked, so I've made some minor visual and UX adjustments, mainly:

• The items are more compact and the license label is no longer misaligned with the image/text
• The asset name is no longer clickable without it having any effect when the same Item node is used inside of the description window
• Added tooltips to the asset author and license labels
• The preview UI in the description window is now hidden when the asset does not have any preview media to show, like code-only assets.
• Clicking on the author now redirects to the asset store web, filtering by it. This is the one that I'd need some maintainer feedback on: I made it so that it would do nothing (like before) when the repository is not the default Godot one, since I'm not entirely sure if alternate repositories would benefit from linking to the main asset library. The alternative to this implementation could be just making this a label like the license one, since right now it's a confusing that it's clickable but nothing happens.

Before/After:

[Calinou]

Tested locally, it mostly works as expected.

• Added tooltips to the asset author and license labels

I noticed this tooltip is visible in the asset list, but not in the asset details popup (where author name isn't clickable). In comparison, the license tooltip appears in both (even though it's clickable in neither case).

[ckaiser]

I noticed this tooltip is visible in the asset list, but not in the asset details popup (where author name isn't clickable). In comparison, the license tooltip appears in both (even though it's clickable in neither case).

Oh yeah, I missed that, thanks!. Using MOUSE_FILTER_IGNORE to avoid LinkButton changing the cursor and hover text color had that unintended side effect, fixed.

[Calinou]

Should be good to merge after applying the suggestion.

[akien-mga]

Thanks!