ProgramMemory refactor - eliminate copies of memory (#5273)

* refactor program memory for encapsulation and remove special treatment of return values

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

* Refactor ProgramMemory to isolate mutation

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

* Refactor ProgramMemory

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

* Generated output

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

* Cache the result of executing modules for their items

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

* Compress envs when popped

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

* Remove the last traces of geometry from the memory module

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

* docs

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

* Fixups

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

* Frontend

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

* Improve Environment GC

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

* Fixup mock execution frontend and interpreter, misc bug fixes

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

---------

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

src/wasm-lib/kcl/tests/if_else/program_memory.snap

@@ -1,8 +1,6 @@
 ---
 source: kcl/src/simulation_tests.rs
-assertion_line: 92
 description: Program memory after executing if_else.kcl
-snapshot_kind: text
 ---
 {
   "environments": [
@@ -68,9 +66,13 @@ snapshot_kind: text
           ]
         }
       },
+      "snapshots": [],
       "parent": null
     }
   ],
-  "currentEnv": 0,
-  "return": null
+  "currentEnv": [
+    0,
+    0
+  ],
+  "callStack": []
 }