Show NestedInputs in the Inputs panel of the parent artboard

One feature missing from the nested inputs implementation was the ability to see the nested input values in the parent artboard's input panel. This update adds this feature, grouping the nested input by its nested artboard.

https://github.com/rive-app/rive/assets/186340/6892826f-14e0-46e7-a9bf-e629e005e85c

Diffs=
3b32d2431 Show NestedInputs in the Inputs panel of the parent artboard (#6107)

Co-authored-by: Philip Chung <philterdesign@gmail.com>

.rive_head

diff --git a/.rive_head b/.rive_head
index 570b935..3b7e4bf 100644
--- a/.rive_head
+++ b/.rive_head
@@ -1 +1 @@
-7227975fb1afd53cbb9d5c6c3149db17606a606f
+3b32d24314be7d877a11b8069622d6d6115383b7

dev/defs/animation/state_machine_component_nested_artboard.json

diff --git a/dev/defs/animation/state_machine_component_nested_artboard.json b/dev/defs/animation/state_machine_component_nested_artboard.json
new file mode 100644
index 0000000..431b95b
--- /dev/null
+++ b/dev/defs/animation/state_machine_component_nested_artboard.json
@@ -0,0 +1,23 @@
+{
+  "name": "StateMachineComponentNestedArtboard",
+  "key": {
+    "int": 172,
+    "string": "statemachinecomponentnestedartboard"
+  },
+  "extends": "animation/state_machine_component_folder.json",
+  "runtime": false,
+  "properties": {
+    "nestedArtboardId": {
+      "type": "Id",
+      "typeRuntime": "uint",
+      "initialValue": "Core.missingId",
+      "initialValueRuntime": "-1",
+      "key": {
+        "int": 404,
+        "string": "nestedartboardid"
+      },
+      "description": "Id of the Artboard represented by this component.",
+      "runtime": false
+    }
+  }
+}
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dev/defs/animation/state_machine_nested_input.json

diff --git a/dev/defs/animation/state_machine_nested_input.json b/dev/defs/animation/state_machine_nested_input.json
new file mode 100644
index 0000000..633b1ab
--- /dev/null
+++ b/dev/defs/animation/state_machine_nested_input.json
@@ -0,0 +1,23 @@
+{
+  "name": "StateMachineNestedInput",
+  "key": {
+    "int": 173,
+    "string": "statemachinenestedinput"
+  },
+  "extends": "animation/state_machine_component.json",
+  "runtime": false,
+  "properties": {
+    "nestedInputId": {
+      "type": "Id",
+      "typeRuntime": "uint",
+      "initialValue": "Core.missingId",
+      "initialValueRuntime": "-1",
+      "key": {
+        "int": 403,
+        "string": "nestedinputid"
+      },
+      "description": "Id of the NestedInput.",
+      "runtime": false
+    }
+  }
+}
\ No newline at end of file