Color Picker Widget

[VisenDev]

Add support for a specialized color picker widget similar to the following.

. The current implementation of a basic color picker in src/Example.zig looks like this

// Let's wrap the sliderEntry widget so we have 3 that represent a Color
pub fn rgbSliders(src: std.builtin.SourceLocation, color: *dvui.Color, opts: Options) !void {
    var hbox = try dvui.box(src, .horizontal, opts);
    defer hbox.deinit();

    var red: f32 = @floatFromInt(color.r);
    var green: f32 = @floatFromInt(color.g);
    var blue: f32 = @floatFromInt(color.b);

    _ = try dvui.sliderEntry(@src(), "R: {d:0.0}", .{ .value = &red, .min = 0, .max = 255, .interval = 1 }, .{ .gravity_y = 0.5 });
    _ = try dvui.sliderEntry(@src(), "G: {d:0.0}", .{ .value = &green, .min = 0, .max = 255, .interval = 1 }, .{ .gravity_y = 0.5 });
    _ = try dvui.sliderEntry(@src(), "B: {d:0.0}", .{ .value = &blue, .min = 0, .max = 255, .interval = 1 }, .{ .gravity_y = 0.5 });

    color.r = @intFromFloat(red);
    color.g = @intFromFloat(green);
    color.b = @intFromFloat(blue);
}