Refactor map and record representation

Replaces the use of `BTreeMap` and `HashMap` for maps and records with
`Vec<(Keyword, Value)>` and `Vec<(Keyword, StaticType)>`. This
simplifies the data structure and allows for ordered iteration, which is
important for serialization and comparison.

Also updates the `unpack` function in `vm.rs` to handle records as well
as lists when destructuring.

examples/record_to_tuple.myc

@@ -0,0 +1,10 @@
+;; Record to Tuple Mapping Test
+;; Output: 30
+(do
+  (def rec {:x 10 :y 20})
+  
+  ;; Map record to tuple pattern
+  (def add-tuple (fn [[a b]] (+ a b)))
+  
+  (add-tuple rec)
+)