feat(prefer-single-binding): add rule

[Olovyannikov]

Closes #116

Why is this important?

Performance

Each useUnit call creates its own subscription management overhead. Combining them reduces:

• Number of hook calls
• Subscription management overhead
• Re-render coordination complexity

Code clarity

A single useUnit call makes it easier to:

• See all dependencies at a glance
• Understand component's reactive logic
• Maintain and refactor code

Example

// correct
const Component = () => {
  const [value, setValue] = useUnit([$store, storeUpdated]);
}

// incorrect
const Component = () => {
  const [value] = useUnit([$store]);
  const [setValue] = useUnit([storeUpdated]);
}

Separate stores and events calls

If you want to separate stores and events as independent groups, you can use option allowSeparateStoresAndEvents

When set to true, allows separate useUnit calls for stores and events, but still enforces combining multiple calls within each group.

Example

// correct
const Component = () => {
  const [value, setValue] = useUnit([$store, storeUpdated]);
}

// if `enforceStoresAndEventsSeparation` flag is on:
const Component = () => {
  const [value, setValue] = useUnit([$store, storeUpdated]);
  
   // will be transformed to:
   
  const [value] = useUnit([$store]);
  const [setValue] = useUnit([storeUpdated])
}

// also correct
const Component = () => {
  const [value] = useUnit([$store]);
  const [setValue] = useUnit([storeUpdated]);
}

// incorrect
const Component = () => {
  const [value] = useUnit([$store]);
  const [setValue] = useUnit([storeUpdated]);
  const [setAnotherValue] = useUnit([thirdEvent]);
}

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