Use only non external only format modifiers
kpipewire doesn't support texture formats that require external samplers. It's also reasonable to match what kwin does.
Also, avoid adding the implicit modifier to the usable modifier list if all modifiers reported by the driver have been rejected. That is a heuristic to determine whether implicit modifiers can be used too, this matches the kwin logic.
(cherry picked from commit 1058e3af)
Co-authored-by: Vlad Zahorodnii vlad.zahorodnii@kde.org