Clean up the code related to root and root_url

[abidlabs]

All the code to resolve URL paths correctly with root and root_url has gotten quite messy.

It would be good to clean this up. In particular, now that replicas use subdirectories instead of subdomains, we can revert most of the changes we made in PRs #5776 and instead just use the same logic we use for the regular fastapi root path.

For clarity, we should also rename root_url to remote_url or something.

[HeetVekariya]

I would like to work on this issue.
As i am new to this repo, can you please locate the files that is to be refactored ?

[abidlabs]

Hi @HeetVekariya this isn't an issue I'd suggest if you are new to the repo, as there is some internal discussion and context that is important. Instead, I'd suggest picking one of the issues from this list: https://github.com/gradio-app/gradio/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22

[abidlabs]

Let's rename root_url to _remote_url to designate it as an internal parameter in the component classes

[abidlabs]

Also see this internal discussion

[abidlabs]

Closed on v4!