Investigate passthrough for `parse_url` on Builders

[kevinjqliu]

Please proceed with this one! The change is reasonable since the "dual-stack endpoint" conforms to a pre-defined shape.

I was pointing out that parse_url currently rejects urls that does not conform to the pre-defined shapes. To support "dual-stack endpoint", we have to add it as a approved shape. Alternatively, we can allow parse_url to passthrough any given url it does not recognize and set self.endpoint accordingly. This way, perhaps we did not need to add the special logic for "dual-stack endpoint" and can also future proof any other url format AWS decides to create.

This was an idea based on #711 where we once again had to allowlist a pre-defined shape into the url parsing logic for Azure/OneLake.

Originally posted by @kevinjqliu in #780 (comment)

[alamb]

Yeah in in my mind if a user provides a Url to the builder then that is the url that should get used

So for example in the S3 builder
https://docs.rs/object_store/latest/object_store/aws/struct.AmazonS3Builder.html

If a user provided the URL directly, we wouldn't then try and parse the relevant pieces and then reform the acutal url during build()