Add support for setting the spread method for gradient fills (#3953)

* Add spread method support for gradients

* Add GradientSpreadMethod enum (Pad, Repeat, Reflect) to vector-types

* Add radio buttons to gradient tool and fill properties panel

* Convert spread method when importing SVGs via usvg

* Sync backup gradient input when changing spread method

* Table<GradientStops> rendering is not yet updated for spread method

* Sync gradient tool options with layer's gradient

* Sync gradient_type and spread_method from the selected
  layer's existing gradient to the tool options bar when
  switching to the gradient tool

* Refactor has_gradient_on_selected_layers
  to reuse a new get_gradient_on_selected_layer helper

* Swap Reflect and Repeat order in UI radio buttons

* Fix alignment of the radio buttons in right panel

* Fix the position of the radio buttons in the tool

* Rename SpreadMethod to SetSpreadMethod

* Move default spread method omission logic

node-graph/libraries/rendering/src/renderer.rs

@@ -24,6 +24,7 @@ use std::fmt::Write;
 use std::hash::{Hash, Hasher};
 use std::ops::Deref;
 use std::sync::{Arc, LazyLock};
+use vector_types::gradient::GradientSpreadMethod;
 use vello::*;
 
 /// Cached 16x16 transparency checkerboard image data (two 8x8 cells of #ffffff and #cccccc).
@@ -1159,6 +1160,11 @@ impl Render for Table<Vector> {
 								.into()
 							}
 						},
+						extend: match gradient.spread_method {
+							GradientSpreadMethod::Pad => peniko::Extend::Pad,
+							GradientSpreadMethod::Reflect => peniko::Extend::Reflect,
+							GradientSpreadMethod::Repeat => peniko::Extend::Repeat,
+						},
 						stops,
 						interpolation_alpha_space: peniko::InterpolationAlphaSpace::Premultiplied,
 						..Default::default()