chore: return memory tests back (#1950)

This resolves INT-4550.

Merkle tests checked that, when we touch some memory,
- the finalized root that is obtained by "build a tree on initial
memory, then update with the touched memory" is the same as if we just
built the tree on the final memory,
- the merkle trace does the interactions we want it to.

I updated them so that they check the same but use the new architecture.

The general memory tests checked that we can do all kinds of accesses
(persistent/volatile, native/rv32 address space, etc etc) and nothing
breaks. Apparently, I did the same in `online.rs`, so I just moved my
tests to that file, where I think they indeed belong.

Author: Golovanov399

crates/vm/src/system/memory/adapter/mod.rs

@@ -41,8 +41,6 @@ use crate::{
 mod air;
 mod columns;
 pub mod records;
-#[cfg(test)]
-mod tests;
 
 #[derive(Setters)]
 pub struct AccessAdapterInventory<F> {

crates/vm/src/system/memory/adapter/tests.rs

@@ -21,9 +21,8 @@ pub use columns::*;
 pub(super) use trace::SerialReceiver;
 pub use tree::*;
 
-// TODO: add back
-// #[cfg(test)]
-// mod tests;
+#[cfg(test)]
+mod tests;
 
 pub struct MemoryMerkleChip<const CHUNK: usize, F> {
     pub air: MemoryMerkleAir<CHUNK>,