[Typing] Add pyright config to suppress warnings

VSCode uses pylance/pyright, a performant type checker. So
setup the builtins used by Deluge and set missing imports to
informational due to OS-specific imports.

It might be possible using extraPaths with extra stubs or use
defineConstants to make pyright not check Windows or Macos conditional
paths but that would require changing all usage so leaving for another
time.

Refs: https://github.com/microsoft/pyright/blob/main/docs/configuration.md
Refs: https://github.com/microsoft/pyright/blob/main/docs/builtins.md

__builtins__.pyi

@@ -0,0 +1,6 @@
+from twisted.web.http import Request
+
+__request__: Request
+
+def _(string: str) -> str: ...
+def _n(string: str) -> str: ...

pyproject.toml

@@ -58,3 +58,7 @@ extend-function-names = ["_n"]
 "deluge/**/gtkui.py" = ["E402"]
 "deluge/plugins/Stats/deluge_stats/graph.py" = ["E402"]
 "deluge/ui/gtk3/*.py" = ["E402"]
+
+[tool.pyright]
+reportMissingImports = "information"
+reportMissingModuleSource = "information"