perf: Add special case to Table.add_rows to increase performance (#608

)

See #606 

### Summary of Changes

perf: Add special case to `Table.add_rows` to increase performance

---------

Co-authored-by: megalinter-bot <129584137+megalinter-bot@users.noreply.github.com>
Co-authored-by: WinPlay02 <winplay02_gh@woberlaender.de>

src/safeds/data/tabular/containers/_table.py

@@ -1057,7 +1057,7 @@ def add_rows(self, rows: list[Row] | Table) -> Table:
         2  5  6
         """
         if isinstance(rows, Table):
-            if rows.number_of_rows == 0:
+            if rows.number_of_columns == 0:
                 return self
             if self.number_of_columns == 0:
                 return rows
@@ -1069,6 +1069,10 @@ def add_rows(self, rows: list[Row] | Table) -> Table:
                         key={val: ix for ix, val in enumerate(self.column_names)}.__getitem__,
                     ),
                 )
+            if rows.number_of_rows == 0:
+                return self
+            if self.number_of_rows == 0:
+                return rows
 
             new_df = pd.concat([self._data, rows._data]).infer_objects()
             new_df.columns = self.column_names

tests/safeds/data/tabular/containers/_table/test_add_rows.py

@@ -25,7 +25,7 @@
             Table({"col1": ["a", "b", "c"], "col2": [1, 2, 4]}),
             [],
             Table({"col1": ["a", "b", "c"], "col2": [1, 2, 4]}),
-        )
+        ),
     ],
     ids=["Rows with string and integer values", "different schema", "empty", "add empty"],
 )
@@ -63,8 +63,26 @@ def test_should_add_rows(table1: Table, rows: list[Row], table2: Table) -> None:
             Table({"col1": [5, "7"], "col2": [6, None]}),
             Table({"col1": [1, 2, 1, 5, "7"], "col2": [1, 2, 4, 6, None]}),
         ),
+        (
+            Table({"col1": [], "yikes": []}),
+            Table({"col1": [2], "yikes": [5]}),
+            Table({"col1": [2], "yikes": [5]}),
+        ),
+        (
+            Table({"col1": [2], "yikes": [5]}),
+            Table({"col1": [], "yikes": []}),
+            Table({"col1": [2], "yikes": [5]}),
+        ),
+    ],
+    ids=[
+        "Rows from table",
+        "add empty to table",
+        "add on empty table",
+        "rowless",
+        "different schema",
+        "same schema add to no rows",
+        "same schema add no rows",
     ],
-    ids=["Rows from table", "add empty to table", "add on empty table", "rowless", "different schema"],
 )
 def test_should_add_rows_from_table(table1: Table, table2: Table, expected: Table) -> None:
     table1 = table1.add_rows(table2)