Improve (and fix some) test finalization (#838)

- Remove some duplicate checks from pylint
- Make Mocks private to the module
- Import module from `typing`
- Allow passing the mocker in the constructor
- Make `MockMicrogrid` an async context manager
- Use the `MockMicrogrid` as an async context manager
- Improve finalization of power distributing tests
- Improve finalization of voltage streamer tests
- Improve finalization of logical meter tests
- Improve finalization of formula formatter tests
- Improve finalization of EV charger pool tests
- Improve finalization of formula composition tests
- Improve finalization of battery status tests
- Improve finalization of grid tests
- Disable pylint check only in one line

pyproject.toml

@@ -155,8 +155,10 @@ disable = [
   "unsubscriptable-object",
   # Checked by flake8
   "line-too-long",
-  "unused-variable",
+  "redefined-outer-name",
   "unnecessary-lambda-assignment",
+  "unused-import",
+  "unused-variable",
 ]
 
 [tool.pylint.design]