Fixes #17 - Allow Graph rendering without tags or nodes

[jhhb]

Summary of changes

• Added a function to sanitize server response
• updated types to reflect that the server response can contain nulls
• Renamed OrgRoamGraphReponse to OrgRoamGraphResponse and removed an unused import in the process of renaming

QA

• Here is a before/after video showing the result running on main versus this PR branch

before-after-17.mp4

Caveats

• I regenerated the Next.js build output, but wasn't sure if these get regenerated as part of CI. I can easily remove this commit.

[kirillrogovoy]

Thanks, James!

@jhhb just pointing out that you've made a PR from one branch of your repo to the other branch (main) of your repo.

Merging it won't get those changes to https://github.com/org-roam/org-roam-ui

[kirillrogovoy]

Are there cases when any of these properties are null/undefined?

@ThomasFKJorna was it a bug or some expected behavior?

I'd rather have those fields always present and assume they are fine on the client.

[jhhb]

Since there might be more discussion here (and I've made this PR against my fork 😬 ) I'm going to close this PR and just make a new issue in org-roam-ui directly. I will also follow-up on the comments I can answer there.