Divorce JSON and KCL (#4436)

Removes JSON from the KCL object model. Closes https://github.com/KittyCAD/modeling-app/issues/1130 -- it was filed on Nov 27 last year. Hopefully I close it before its one year anniversary.

Changes:

- Removed the UserVal variant from `enum KclValue`. That variant held JSON data.
- Replaced it with several new variants like Number, String, Array (of KCL values), Object (where keys are String and values are KCL values)
- Added a dedicated Sketch variant to KclValue. We used to have a variant like this, but I removed it as an experimental approach to fix this issue. Eventually I decided to undo it and use the approach of this PR instead.
- Removed the `impl_from_arg_via_json` macro, which implemented conversion from KclValue to Rust types by matching the KclValue to its UserVal variant, grabbing the JSON, then deserializing that into the desired Rust type. 
- Instead, replaced it with manual conversion from KclValue to Rust types, using some convenience macros like `field!`

src/lang/executor.test.ts

@@ -58,7 +58,13 @@ const newVar = myVar + 1`
 `
     const mem = await exe(code)
     // geo is three js buffer geometry and is very bloated to have in tests
-    const minusGeo = mem.get('mySketch')?.value?.paths
+    const sk = mem.get('mySketch')
+    expect(sk?.type).toEqual('Sketch')
+    if (sk?.type !== 'Sketch') {
+      return
+    }
+
+    const minusGeo = sk?.value?.paths
     expect(minusGeo).toEqual([
       {
         type: 'ToPoint',
@@ -150,7 +156,7 @@ const newVar = myVar + 1`
     ].join('\n')
     const mem = await exe(code)
     expect(mem.get('mySk1')).toEqual({
-      type: 'UserVal',
+      type: 'Sketch',
       value: {
         type: 'Sketch',
         on: expect.any(Object),
@@ -215,7 +221,6 @@ const newVar = myVar + 1`
         id: expect.any(String),
         __meta: [{ sourceRange: [39, 63, 0] }],
       },
-      __meta: [{ sourceRange: [39, 63, 0] }],
     })
   })
   it('execute array expression', async () => {
@@ -225,7 +230,7 @@ const newVar = myVar + 1`
     const mem = await exe(code)
     // TODO path to node is probably wrong here, zero indexes are not correct
     expect(mem.get('three')).toEqual({
-      type: 'UserVal',
+      type: 'Int',
       value: 3,
       __meta: [
         {
@@ -234,8 +239,17 @@ const newVar = myVar + 1`
       ],
     })
     expect(mem.get('yo')).toEqual({
-      type: 'UserVal',
-      value: [1, '2', 3, 9],
+      type: 'Array',
+      value: [
+        { type: 'Int', value: 1, __meta: [{ sourceRange: [28, 29, 0] }] },
+        { type: 'String', value: '2', __meta: [{ sourceRange: [31, 34, 0] }] },
+        { type: 'Int', value: 3, __meta: [{ sourceRange: [14, 15, 0] }] },
+        {
+          type: 'Number',
+          value: 9,
+          __meta: [{ sourceRange: [43, 44, 0] }, { sourceRange: [47, 48, 0] }],
+        },
+      ],
       __meta: [
         {
           sourceRange: [27, 49, 0],
@@ -253,8 +267,25 @@ const newVar = myVar + 1`
     ].join('\n')
     const mem = await exe(code)
     expect(mem.get('yo')).toEqual({
-      type: 'UserVal',
-      value: { aStr: 'str', anum: 2, identifier: 3, binExp: 9 },
+      type: 'Object',
+      value: {
+        aStr: {
+          type: 'String',
+          value: 'str',
+          __meta: [{ sourceRange: [34, 39, 0] }],
+        },
+        anum: { type: 'Int', value: 2, __meta: [{ sourceRange: [47, 48, 0] }] },
+        identifier: {
+          type: 'Int',
+          value: 3,
+          __meta: [{ sourceRange: [14, 15, 0] }],
+        },
+        binExp: {
+          type: 'Number',
+          value: 9,
+          __meta: [{ sourceRange: [77, 78, 0] }, { sourceRange: [81, 82, 0] }],
+        },
+      },
       __meta: [
         {
           sourceRange: [27, 83, 0],
@@ -268,11 +299,11 @@ const newVar = myVar + 1`
     )
     const mem = await exe(code)
     expect(mem.get('myVar')).toEqual({
-      type: 'UserVal',
+      type: 'String',
       value: '123',
       __meta: [
         {
-          sourceRange: [41, 50, 0],
+          sourceRange: [19, 24, 0],
         },
       ],
     })
@@ -356,7 +387,26 @@ describe('testing math operators', () => {
   it('with unaryExpression in ArrayExpression', async () => {
     const code = 'const myVar = [1,-legLen(5, 4)]'
     const mem = await exe(code)
-    expect(mem.get('myVar')?.value).toEqual([1, -3])
+    expect(mem.get('myVar')?.value).toEqual([
+      {
+        __meta: [
+          {
+            sourceRange: [15, 16, 0],
+          },
+        ],
+        type: 'Int',
+        value: 1,
+      },
+      {
+        __meta: [
+          {
+            sourceRange: [17, 30, 0],
+          },
+        ],
+        type: 'Number',
+        value: -3,
+      },
+    ])
   })
   it('with unaryExpression in ArrayExpression in CallExpression, checking nothing funny happens when used in a sketch', async () => {
     const code = [