Macro for parsing KCL at Rust compile-time (#1049)

Macro for parsing KCL at Rust compile-time

This adds a new `parse_kcl!` macro which takes a string as input. It parses the string into KCL source code _at compile-time_. Invalid KCL will make your Rust project fail to compile.

Fixes https://github.com/KittyCAD/modeling-app/issues/1018

src/wasm-lib/kcl-macros/tests/macro_test.rs

@@ -0,0 +1,38 @@
+extern crate alloc;
+use kcl_lib::ast::types::{
+    BodyItem, Identifier, Literal, LiteralValue, NonCodeMeta, Program, Value, VariableDeclaration, VariableDeclarator,
+    VariableKind,
+};
+use kcl_macros::parse;
+use pretty_assertions::assert_eq;
+
+#[test]
+fn basic() {
+    let actual = parse!("const y = 4");
+    let expected = Program {
+        start: 0,
+        end: 11,
+        body: vec![BodyItem::VariableDeclaration(VariableDeclaration {
+            start: 0,
+            end: 11,
+            declarations: vec![VariableDeclarator {
+                start: 6,
+                end: 11,
+                id: Identifier {
+                    start: 6,
+                    end: 7,
+                    name: "y".to_owned(),
+                },
+                init: Value::Literal(Box::new(Literal {
+                    start: 10,
+                    end: 11,
+                    value: LiteralValue::IInteger(4),
+                    raw: "4".to_owned(),
+                })),
+            }],
+            kind: VariableKind::Const,
+        })],
+        non_code_meta: NonCodeMeta::default(),
+    };
+    assert_eq!(expected, actual);
+}