Some small improvements

Author: chandr-andr

src/driver/cursor.rs

@@ -58,7 +58,10 @@ impl Cursor {
                 .await?;
 
             if result.is_empty() {
-                return Err(PyStopAsyncIteration::new_err("Error").into());
+                return Err(PyStopAsyncIteration::new_err(
+                    "Iteration is over, no more results in cursor",
+                )
+                .into());
             };
 
             Ok(PSQLDriverPyQueryResult::new(result))

src/value_converter.rs

@@ -483,7 +483,7 @@ pub fn postgres_to_py(
     }
 }
 
-/// Convert python List of Dict type in serde `Value`.
+/// Convert python List of Dict type or just Dict in serde `Value`.
 ///
 /// # Errors
 /// May return error if cannot convert Python type into Rust one.