LibWeb: Add imports to all IDL files that depend on others

Author: https://github.com/alimpfard
Commit: a59800b4a0
Pull-request: https://github.com/SerenityOS/serenity/pull/12548
Reviewed-by: https://github.com/awesomekling
Reviewed-by: https://github.com/linusg

Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.idl

@@ -1,3 +1,9 @@
+#import <HTML/HTMLCanvasElement.idl>
+#import <HTML/HTMLImageElement.idl>
+#import <HTML/ImageData.idl>
+#import <HTML/TextMetrics.idl>
+#import <HTML/CanvasGradient.idl>
+
 interface CanvasRenderingContext2D {
 
     undefined fillRect(double x, double y, double w, double h);