Slimmer implementation of credit-only accounts (#4592)

* Add credit-only debit/data check to verify_instruction

* Store credits and pass to accounts_db

* Add InstructionErrors and tests

* Relax account locks for credit-only accounts

* Collect credit-only account credits before passing to accounts_db to store properly

* Convert System Transfer  accounts to credit-only, and fixup test

* Functionalize collect_accounts to unit test

* Review comments

* Rebase

runtime/src/append_vec.rs

@@ -220,13 +220,16 @@ impl AppendVec {
     }
 
     #[allow(clippy::mutex_atomic)]
-    pub fn append_accounts(&self, accounts: &[(StorageMeta, &Account)]) -> Vec<usize> {
+    pub fn append_accounts(
+        &self,
+        accounts: &[(StorageMeta, &Pubkey, &Account, u64)],
+    ) -> Vec<usize> {
         let mut offset = self.append_offset.lock().unwrap();
         let mut rv = vec![];
-        for (storage_meta, account) in accounts {
+        for (storage_meta, _, account, lamports) in accounts {
             let meta_ptr = storage_meta as *const StorageMeta;
             let balance = AccountBalance {
-                lamports: account.lamports,
+                lamports: *lamports,
                 owner: account.owner,
                 executable: account.executable,
             };
@@ -248,7 +251,7 @@ impl AppendVec {
     }
 
     pub fn append_account(&self, storage_meta: StorageMeta, account: &Account) -> Option<usize> {
-        self.append_accounts(&[(storage_meta, account)])
+        self.append_accounts(&[(storage_meta, &Pubkey::default(), account, account.lamports)])
             .first()
             .cloned()
     }