Clearly show the architecture the package is available for

[hfiguiere]

Today, there is still confusion when users try to install packages that are not available for their architecture. It is usually Chromebook users (arm or aarch64 platform) for packages that are Intel only and all they get is a "package not found" error.

The details page should display:

• architecture the package is available for
• a clear mention that the package might not be available for architecture the user runs (by checking the User-Agent)

[hfiguiere]

Likely requires flathub-infra/backend#16 first.

[theofficialgman]

Can we get this implemented finally now that the blocker is gone?

I'd like for the supported architectures to be shown prominintly as well as filtering options available so I can hide non-compatible apps