Redesign how the control bar handles fill and stroke colors (#4137)

* Revamp how the control bar handles fill and stroke colors

* Fix bugs

* Code review

editor/src/messages/layout/utility_types/widgets/button_widgets.rs

@@ -202,6 +202,13 @@ pub struct ColorInput {
 	#[serde(rename = "menuDirection")]
 	pub menu_direction: Option<MenuDirection>,
 	pub disabled: bool,
+	pub mixed: bool,
+
+	// Sizing
+	#[serde(rename = "minWidth")]
+	pub min_width: u32,
+	#[serde(rename = "maxWidth")]
+	pub max_width: u32,
 
 	// Styling
 	pub narrow: bool,

editor/src/messages/layout/utility_types/widgets/input_widgets.rs

@@ -20,6 +20,7 @@ pub struct CheckboxInput {
 	#[serde(rename = "forLabel")]
 	pub for_label: CheckboxId,
 	pub disabled: bool,
+	pub mixed: bool,
 
 	// Tooltips
 	#[serde(rename = "tooltipLabel")]