Auto merge of #16067 - Wafflespeanut:grid, r=nox,Wafflespeanut

Stylo: Add support for grid-template-{rows,columns}

This has the implementation of grid's `<track-list>` nightmare.

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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #15311

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- [x] There are tests for these changes

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components/style/gecko/generated/bindings.rs

@@ -1,6 +1,7 @@
 /* automatically generated by rust-bindgen */
 
-pub use nsstring::{nsACString, nsAString, nsString};
+pub use nsstring::{nsACString, nsAString, nsString, nsStringRepr};
+use gecko_bindings::structs::nsTArray;
 type nsACString_internal = nsACString;
 type nsAString_internal = nsAString;
 use gecko_bindings::structs::mozilla::css::GridTemplateAreasValue;
@@ -943,6 +944,15 @@ extern "C" {
 extern "C" {
     pub fn Gecko_DropElementSnapshot(snapshot: ServoElementSnapshotOwned);
 }
+extern "C" {
+    pub fn Gecko_ResizeTArrayForStrings(array: *mut nsTArray<nsStringRepr>,
+                                        length: u32);
+}
+extern "C" {
+    pub fn Gecko_SetStyleGridTemplateArrayLengths(grid_template:
+                                                      *mut nsStyleGridTemplate,
+                                                  track_sizes: u32);
+}
 extern "C" {
     pub fn Gecko_CopyStyleGridTemplateValues(grid_template:
                                                  *mut nsStyleGridTemplate,