Add option to enter endpoint URL (fix #116)

[FluorescentHallucinogen]

This pull request adds new "URL" tab into "Change schema" dialog to enter endpoint URL.

Before:

After:

[FluorescentHallucinogen]

@IvanGoncharov Thanks for your comments! They are all great points. But I don't plan to fix them as part of this pull request because they are out of scope.

I'm guided by Google's Engineering Practices.

TL;DR: The product/code should get better than before merging a change, even if it isn’t perfect.

Before merging my change, users couldn't enter GraphQL endpoint URLs at all. After merging, they could. So the product is in better state than before. The quality of my change is not lower than the quality of the code. So it doesn't degrade the overall code health.

Nevertheless, I would be happy to fix them (and some other UI/UX issues I found) in the next iteration as a separate pull request. :wink:

[FluorescentHallucinogen]

Deployed a live demo: https://graphql-voyager.web.app.

[FluorescentHallucinogen]

Updated live demo: https://graphql-voyager.web.app.

[ravisastryk]

This is an excellent feature that helps navigate the graph especially when there are multiple services which are federated. We have a use case where we would like to specify URL and let the voyager render the graph. Appreciate if this can be merged.

[nohehf]

Hey @IvanGoncharov, what's the state of this feature request? If the MR is too old to be merged I'll be happy to open a new mr with those changes (and we can discuss which changes to implement). I think this feature is a great UX / quality of life improvement to the product and should be considered.