Add support for react hook enabled flag

[doanhtu07]

Background

Hi all, I was playing around with ElectricSQL and noticed that it couldn't stop polling even when a React component already unmounted.

Then, I saw your text on the main doc here: https://electric-sql.com/docs/integrations/react#how-to-abort-a-shape-subscription-%E2%80%94-abortcontroller

I also found this issue: #2212

How this solution works

packages/typescript-client/src/shape.ts

• Introduce a way to not auto-start the stream whenever we create a new shape
• So client will have more control over the lifecycle of the stream

packages/typescript-client/src/client.ts

• Introduce pause and resume actions
• Client can use these actions to actively pause or resume the stream

packages/react-hooks/src/react-hooks.tsx

• Use a map to count references to a stream
• If the count drops to 0, pause the stream
• If the count reaches 1, resume the stream

Notes

Let me know what you think

Note that I've not worked on the second half of issue 2212

• "auto-pause long polling from useShape after the user has been inactive for so long and reactivate it when the user is active again"