config: expose timeouts in http config

- `read_timeout` timeout for reading new data portions from the peer
- `connect_timeout` timeout for establishing new connections

For more information about individual timeouts meanings:

- `read_timeout` maps to `aiohttp`'s `sock_read` timeout
- `connect_timeout` applies to `aiohttp`'s `connect`, `sock_connect`
  timeouts

https://docs.aiohttp.org/en/stable/client_reference.html?highlight=clienttimeout#clienttimeout

dvc/config_schema.py

@@ -97,6 +97,8 @@ HTTP_COMMON = {
     "ask_password": Bool,
     "ssl_verify": Any(Bool, str),
     "method": str,
+    "connect_timeout": All(Coerce(float), Range(0, min_included=True)),
+    "read_timeout": All(Coerce(float), Range(0, min_included=True)),
     Optional("verify", default=False): Bool,
 }
 WEBDAV_COMMON = {