Rename MemoryItem to KclValue (#3378)

As @jon points out, "It's not only used in ProgramMemory. It's also
used as the return value of functions and as what gets substituted in
for the pipe substitution symbol %"

src/wasm-lib/kcl/src/std/shapes.rs

@@ -8,7 +8,7 @@ use serde::{Deserialize, Serialize};
 use crate::{
     ast::types::TagDeclarator,
     errors::KclError,
-    executor::MemoryItem,
+    executor::KclValue,
     std::{Args, SketchGroup, SketchSurface},
 };
 
@@ -22,12 +22,12 @@ pub enum SketchSurfaceOrGroup {
 }
 
 /// Sketch a circle.
-pub async fn circle(args: Args) -> Result<MemoryItem, KclError> {
+pub async fn circle(args: Args) -> Result<KclValue, KclError> {
     let (center, radius, sketch_surface_or_group, tag): ([f64; 2], f64, SketchSurfaceOrGroup, Option<TagDeclarator>) =
         args.get_circle_args()?;
 
     let sketch_group = inner_circle(center, radius, sketch_surface_or_group, tag, args).await?;
-    Ok(MemoryItem::SketchGroup(sketch_group))
+    Ok(KclValue::SketchGroup(sketch_group))
 }
 
 /// Construct a 2-dimensional circle, of the specified radius, centered at