MVP eyedropper tool for fill colors (#300)

* Implement eyedropper for layer fill colors

* Add shortcut for eyedropper

* Add right mouse sampling for secondary color

core/document/src/layers/style/mod.rs

@@ -19,6 +19,9 @@ impl Fill {
 	pub fn new(color: Color) -> Self {
 		Self { color: Some(color) }
 	}
+	pub fn color(&self) -> Option<Color> {
+		self.color
+	}
 	pub fn none() -> Self {
 		Self { color: None }
 	}
@@ -41,6 +44,12 @@ impl Stroke {
 	pub fn new(color: Color, width: f32) -> Self {
 		Self { color, width }
 	}
+	pub fn color(&self) -> Color {
+		self.color
+	}
+	pub fn width(&self) -> f32 {
+		self.width
+	}
 	pub fn render(&self) -> String {
 		format!(r##" stroke="#{}"{} stroke-width="{}""##, self.color.rgb_hex(), format_opacity("stroke", self.color.a()), self.width)
 	}