Correct code_size function implementation (#6304)

## Description
The current code_size function returns a pointer, rather than the value,
this pr corrects this mistake.

## Checklist

- [x] I have linked to any relevant issues.
- [x] I have commented my code, particularly in hard-to-understand
areas.
- [x] I have updated the documentation where relevant (API docs, the
reference, and the Sway book).
- [ ] If my change requires substantial documentation changes, I have
[requested support from the DevRel
team](https://github.com/FuelLabs/devrel-requests/issues/new/choose)
- [x] I have added tests that prove my fix is effective or that my
feature works.
- [x] I have added (or requested a maintainer to add) the necessary
`Breaking*` or `New Feature` labels where relevant.
- [x] I have done my best to ensure that my PR adheres to [the Fuel Labs
Code Review
Standards](https://github.com/FuelLabs/rfcs/blob/master/text/code-standards/external-contributors.md).
- [x] I have requested a review from the relevant team or maintainers.

---------

Co-authored-by: K1-R1 <77465250+K1-R1@users.noreply.github.com>
Co-authored-by: IGI-111 <igi-111@protonmail.com>

sway-lib-std/src/call_frames.sw

@@ -63,10 +63,11 @@ pub fn msg_asset_id() -> AssetId {
 /// }
 /// ```
 pub fn code_size() -> u64 {
-    asm(size, ptr, offset: 576) {
+    let ptr = asm(size, ptr, offset: 576) {
         add size fp offset;
-        size: u64
-    }
+        size: raw_ptr
+    };
+    ptr.read::<u64>()
 }
 
 /// Get the first parameter from the current call frame.

test/src/sdk-harness/test_projects/call_frames/mod.rs

@@ -1,4 +1,3 @@
-use fuel_vm::consts::VM_MAX_RAM;
 use fuels::{accounts::wallet::WalletUnlocked, prelude::*, types::ContractId};
 
 abigen!(Contract(
@@ -36,7 +35,9 @@ async fn can_get_id_contract_id_this() {
 async fn can_get_code_size() {
     let (instance, _id) = get_call_frames_instance().await;
     let result = instance.methods().get_code_size().call().await.unwrap();
-    assert!(is_within_range(result.value));
+    // Check if codesize is between 1000 and 7000. Arbitrary endpoints, current codesize is 6816
+    // but the lower bound future proofs against compiler optimizations
+    assert!(result.value > 1000 && result.value < 7000);
 }
 
 #[tokio::test]
@@ -110,7 +111,3 @@ async fn can_get_second_param_multiple_params2() {
         .unwrap();
     assert_eq!(result.value, (300, expected_struct, expected_struct2));
 }
-
-fn is_within_range(n: u64) -> bool {
-    n > 0 && n <= VM_MAX_RAM
-}