[Fabric] Add support for custom themes and support runtime theme change (#12474)

* [Fabric] Add support for custom theme's, and support runtime theme change

* Change files

* desktop build fix

* format

* fix desktop fabric build

* fix

* fix

* fix

Author: acoates-ms

change/react-native-windows-bd63c12c-5336-4f32-a5f0-2f1b5aed9420.json

@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "[Fabric] Add support for custom theme's, and support runtime theme change",
+  "packageName": "react-native-windows",
+  "email": "[email protected]",
+  "dependentChangeType": "patch"
+}

packages/e2e-test-app-fabric/test/__snapshots__/HomeUIADump.test.ts.snap

@@ -4425,8 +4425,8 @@ exports[`Home UIA Tree Dump Components Tab 1`] = `
               },
               {
                 "Offset": [
-                  0,
-                  0,
+                  -0,
+                  -0,
                   0,
                 ],
                 "Opacity": 1,
@@ -4452,7 +4452,7 @@ exports[`Home UIA Tree Dump Components Tab 1`] = `
               {
                 "Offset": [
                   0,
-                  0,
+                  -0,
                   0,
                 ],
                 "Opacity": 1,
@@ -26397,4 +26397,4 @@ exports[`Home UIA Tree Dump XMLHttpRequest 1`] = `
     "Visual Type": "SpriteVisual",
   },
 }
-`;
+`;