texture_cache: Blacklist BGRA8 copies and views on OpenGL

In order to force the BGRA8 conversion on Nvidia using OpenGL, we need to forbid texture copies and views with other formats.

This commit also adds a boolean relating to this, as this needs to be done only for the OpenGL api, Vulkan must remain unchanged.

src/video_core/renderer_opengl/gl_texture_cache.h

@@ -86,6 +86,11 @@ public:
 
     FormatProperties FormatInfo(VideoCommon::ImageType type, GLenum internal_format) const;
 
+    bool HasNativeBgr() const noexcept {
+        // OpenGL does not have native support for the BGR internal format
+        return false;
+    }
+
     bool HasBrokenTextureViewFormats() const noexcept {
         return has_broken_texture_view_formats;
     }