Type check and coerce arguments to user functions and return values from std Rust functions (#6958)

* Shuffle around function call code

Signed-off-by: Nick Cameron <nrc@ncameron.org>

* Refactor function calls to share more code

Signed-off-by: Nick Cameron <nrc@ncameron.org>

* Hack to leave the result of revolve as a singleton rather than array

Signed-off-by: Nick Cameron <nrc@ncameron.org>

---------

Signed-off-by: Nick Cameron <nrc@ncameron.org>

rust/kcl-lib/src/execution/memory.rs

@@ -820,7 +820,7 @@ impl PartialEq for Stack {
 pub struct EnvironmentRef(usize, usize);
 
 impl EnvironmentRef {
-    fn dummy() -> Self {
+    pub fn dummy() -> Self {
         Self(usize::MAX, 0)
     }