More React hooks and RuntimeScalars

[AlecAivazis]

This PR adds 2 new hooks to the react runtime:

• useLocation returns a Location object containing pathname
• useSession returns the current Session object and a function that can be called on the client to update the session without forcing a hard refresh

I also wanted to play around with the scalar approach discussed in #1211 so I added it behind a feature flag under the key runtimeScalars. If anyone is interested in learning more, I also updated the query variables documentation to showcase how to use it.

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[changeset-bot]

🦋 Changeset detected

Latest commit: 3cdc871

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 8 packages

Name	Type
houdini-react	Patch
houdini	Patch
houdini-adapter-auto	Patch
houdini-adapter-cloudflare	Patch
houdini-adapter-node	Patch
houdini-svelte	Patch
houdini-plugin-svelte-global-stores	Patch
create-houdini	Patch

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