libcamera: stream: Turn StreamRole into scoped enumeration

The StreamRole enum has enumerators such as 'Raw' that are too generic
to be in the global libcamera namespace. Turn it into a scoped enum to
avoid namespace clashes, and update users accordingly.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

include/libcamera/stream.h

@@ -62,7 +62,7 @@ private:
 	StreamFormats formats_;
 };
 
-enum StreamRole {
+enum class StreamRole {
 	Raw,
 	StillCapture,
 	VideoRecording,