fix: added memory_usage to solvers as it is now required in pylops solvers

Author: mrava87SW

pylops_mpi/optimization/cls_basic.py

@@ -51,6 +51,9 @@ def _print_step(self, x: Union[DistributedArray, StackedDistributedArray]) -> No
         print(msg)
         sys.stdout.flush()
 
+    def memory_usage(self) -> None:
+        pass
+
     def setup(
             self,
             y: Union[DistributedArray, StackedDistributedArray],
@@ -299,6 +302,9 @@ def _print_step(self, x: Union[DistributedArray, StackedDistributedArray]) -> No
         print(msg)
         sys.stdout.flush()
 
+    def memory_usage(self) -> None:
+        pass
+
     def setup(self,
               y: Union[DistributedArray, StackedDistributedArray],
               x0: Union[DistributedArray, StackedDistributedArray],