Enable pyright strict mode (#2652)

- added pyrightconfig.json with typeCheckingMode=strict
- added type hints to all files except api.py
- added type stubs for dns, etcd, consul, kazoo, pysyncobj and other modules
- added type stubs for psycopg2 and urllib3 with some little fixes
- fixes most of the issues reported by pyright
- remaining issues will be addressed later, along with enabling CI linting task

typings/consul/__init__.pyi

@@ -0,0 +1,2 @@
+from consul.base import ConsulException, NotFound
+__all__ = ['ConsulException', 'Consul', 'NotFound']

typings/consul/base.pyi

@@ -0,0 +1,24 @@
+from typing import Any, Dict, List, Optional, Tuple
+class ConsulException(Exception): ...
+class NotFound(ConsulException): ...
+class Check:
+    @classmethod
+    def http(klass, url: str, interval: str, timeout: Optional[str] = None, deregister: Optional[str] = None) -> Dict[str, str]: ...
+class Consul:
+    http: Any
+    agent: 'Consul.Agent'
+    session: 'Consul.Session'
+    kv: 'Consul.KV'
+    class KV:
+        def get(self, key: str, index: Optional[int]=None, recurse: bool = False, wait: Optional[str] = None, token: Optional[str] = None, consistency: Optional[str] = None, keys: bool = False, separator: Optional[str] = '', dc: Optional[str] = None) -> Tuple[int, Dict[str, Any]]: ...
+        def put(self, key: str, value: str, cas: Optional[int] = None, flags: Optional[int] = None, acquire: Optional[str] = None, release: Optional[str] = None, token: Optional[str] = None, dc: Optional[str] = None) -> bool: ...
+        def delete(self, key: str, recurse: Optional[bool] = None, cas: Optional[int] = None, token: Optional[str] = None, dc: Optional[str] = None) -> bool: ...
+     class Agent:
+        service: 'Consul.Agent.Service'
+        def self(self) -> Dict[str, Dict[str, Any]]: ...
+        class Service:
+            def register(self, name: str, service_id=..., address=..., port=..., tags=..., check=..., token=..., script=..., interval=..., ttl=..., http=..., timeout=..., enable_tag_override=...) -> bool: ...
+            def deregister(self, service_id: str) -> bool: ...
+    class Session:
+        def create(self, name: Optional[str] = None, node: Optional[str] = [], checks: Optional[List[str]]=None, lock_delay: float = 15, behavior: str = 'release', ttl: Optional[int] = None, dc: Optional[str] = None) -> str: ...
+        def renew(self, session_id: str, dc: Optional[str] = None) -> Optional[str]: ...