Bring back the frequenz.api namespace (#40)

The namespaces makes it easier to differentiate API related
files/modules/packages from other type of software components, like
actors, etc.

This partially reverts 98c13d2b21722a14ae701b23ce06158e0f8b1c63 (the
`v1` addition is kept).

Author: llucax

proto/frequenz/dispatch/v1/dispatch.proto …/frequenz/api/dispatch/v1/dispatch.protoproto/frequenz/dispatch/v1/dispatch.proto renamed to proto/frequenz/api/dispatch/v1/dispatch.proto proto/frequenz/dispatch/v1/dispatch.proto renamed to proto/frequenz/api/dispatch/v1/dispatch.proto

@@ -38,9 +38,8 @@
 
 syntax = "proto3";
 
-package frequenz.dispatch.v1;
+package frequenz.api.dispatch.v1;
 
-import "google/api/annotations.proto";
 import "google/protobuf/empty.proto";
 import "google/protobuf/struct.proto";
 import "google/protobuf/timestamp.proto";

py/frequenz/dispatch/v1/__init__.py py/frequenz/api/dispatch/v1/__init__.pypy/frequenz/dispatch/v1/__init__.py renamed to py/frequenz/api/dispatch/v1/__init__.py

@@ -7,19 +7,19 @@
 def test_package_import() -> None:
     """Test that the package can be imported."""
     # pylint: disable=import-outside-toplevel
-    from frequenz.dispatch import v1
+    from frequenz.api.dispatch import v1
 
     assert v1 is not None
 
 
 def test_module_import_components() -> None:
     """Test that the modules can be imported."""
     # pylint: disable=import-outside-toplevel
-    from frequenz.dispatch.v1 import dispatch_pb2
+    from frequenz.api.dispatch.v1 import dispatch_pb2
 
     assert dispatch_pb2 is not None
 
     # pylint: disable=import-outside-toplevel
-    from frequenz.dispatch.v1 import dispatch_pb2_grpc
+    from frequenz.api.dispatch.v1 import dispatch_pb2_grpc
 
     assert dispatch_pb2_grpc is not None