URL query values are percent-decoded twice #4208

Version: master at 88d16d0db10c852d1d292628b2c832f1ed117056

Redis version: Not applicable; this occurs before connecting to Redis.

Platform: Python 3.10.9 on macOS

Description:

ConnectionPool.from_url decodes URL query values twice:

import redis

pool = redis.ConnectionPool.from_url(
    "redis://localhost?client_name=worker%2520name"
)
print(pool.connection_kwargs["client_name"])

Expected:

worker%20name

Actual:

worker name

This mutates literal percent-encoded sequences in query options, so callers
cannot preserve values such as the intended client name.