Clarify account creation error messages in CLI (#7719)

* Clarify account creation error messages in CLI

* feedback

* Fix rebase

cli/src/stake.rs

@@ -542,12 +542,16 @@ pub fn process_create_stake_account(
         (&stake_account_address, "stake_account".to_string()),
     )?;
 
-    if rpc_client.get_account(&stake_account_address).is_ok() {
-        return Err(CliError::BadParameter(format!(
-            "Unable to create stake account. Stake account already exists: {}",
-            stake_account_address
-        ))
-        .into());
+    if let Ok(stake_account) = rpc_client.get_account(&stake_account_address) {
+        let err_msg = if stake_account.owner == solana_stake_program::id() {
+            format!("Stake account {} already exists", stake_account_address)
+        } else {
+            format!(
+                "Account {} already exists and is not a stake account",
+                stake_account_address
+            )
+        };
+        return Err(CliError::BadParameter(err_msg).into());
     }
 
     let minimum_balance =