chore(stdlib)!: Group mutable/immutable data structures (#1652)

* chore(stdlib)!: Group mutable/immutable data structures

* add submodule tests into submodule within test files

* Apply suggestions from code review

* Regen docs

---------

Co-authored-by: Blaine Bublitz <[email protected]>

Author: alex-snezhko

compiler/test/__snapshots__/provides.82c10ab4.0.snapshot

@@ -11,20 +11,20 @@ provides › provide12
  (import \"GRAIN$MODULE$runtime/gc\" \"GRAIN$EXPORT$malloc\" (global $GRAIN$EXPORT$malloc_0 (mut i32)))
  (import \"GRAIN$MODULE$runtime/gc\" \"GRAIN$EXPORT$incRef\" (global $GRAIN$EXPORT$incRef_0 (mut i32)))
  (import \"GRAIN$MODULE$runtime/gc\" \"GRAIN$EXPORT$decRef\" (global $GRAIN$EXPORT$decRef_0 (mut i32)))
- (import \"GRAIN$MODULE$pervasives\" \"GRAIN$EXPORT$print\" (global $print_1161 (mut i32)))
- (import \"GRAIN$MODULE$providedType\" \"GRAIN$EXPORT$apply\" (global $apply_1159 (mut i32)))
+ (import \"GRAIN$MODULE$pervasives\" \"GRAIN$EXPORT$print\" (global $print_1199 (mut i32)))
+ (import \"GRAIN$MODULE$providedType\" \"GRAIN$EXPORT$apply\" (global $apply_1197 (mut i32)))
  (import \"GRAIN$MODULE$runtime/gc\" \"malloc\" (func $malloc_0 (param i32 i32) (result i32)))
  (import \"GRAIN$MODULE$runtime/gc\" \"incRef\" (func $incRef_0 (param i32 i32) (result i32)))
  (import \"GRAIN$MODULE$runtime/gc\" \"decRef\" (func $decRef_0 (param i32 i32) (result i32)))
- (import \"GRAIN$MODULE$pervasives\" \"print\" (func $print_1161 (param i32 i32) (result i32)))
- (import \"GRAIN$MODULE$providedType\" \"apply\" (func $apply_1159 (param i32 i32) (result i32)))
+ (import \"GRAIN$MODULE$pervasives\" \"print\" (func $print_1199 (param i32 i32) (result i32)))
+ (import \"GRAIN$MODULE$providedType\" \"apply\" (func $apply_1197 (param i32 i32) (result i32)))
  (global $GRAIN$TABLE_SIZE i32 (i32.const 1))
- (elem $elem (global.get $relocBase_0) $lam_lambda_1160)
+ (elem $elem (global.get $relocBase_0) $lam_lambda_1198)
  (export \"memory\" (memory $0))
  (export \"_gmain\" (func $_gmain))
  (export \"_start\" (func $_start))
  (export \"GRAIN$TABLE_SIZE\" (global $GRAIN$TABLE_SIZE))
- (func $lam_lambda_1160 (param $0 i32) (param $1 i32) (result i32)
+ (func $lam_lambda_1198 (param $0 i32) (param $1 i32) (result i32)
   (local $2 i32)
   (local $3 i32)
   (local $4 i32)
@@ -74,10 +74,10 @@ provides › provide12
       )
      )
     )
-    (return_call $print_1161
+    (return_call $print_1199
      (call $incRef_0
       (global.get $GRAIN$EXPORT$incRef_0)
-      (global.get $print_1161)
+      (global.get $print_1199)
      )
      (local.get $8)
     )
@@ -129,10 +129,10 @@ provides › provide12
      )
     )
    )
-   (return_call $apply_1159
+   (return_call $apply_1197
     (call $incRef_0
      (global.get $GRAIN$EXPORT$incRef_0)
-     (global.get $apply_1159)
+     (global.get $apply_1197)
     )
     (local.get $6)
    )