Throttling is a technique to limit how often a function executes.
When a function is throttled with a wait time of X ms:

• The function can run immediately the first time.
• Further calls within the next X ms are ignored.
• Once X ms have passed since the last call, the function can run again.

Your task: Implement throttle(fn, wait) which:

• Accepts a callback fn and a wait duration wait in ms.
• Returns a throttled version of fn that respects the rules above.

Example

let i = 0;
function increment() {
  i++;
}
const throttledIncrement = throttle(increment, 100);

// t = 0 → call runs immediately, i = 1
throttledIncrement(); 

// t = 50 → ignored (less than 100ms since last run), i = 1
throttledIncrement(); 

// t = 101 → allowed (more than 100ms since last run), i = 2
throttledIncrement();

Follow-up:
Enhance throttle to support:

• cancel() method (clear pending executions).
• leading and trailing options (decide whether the function runs immediately, at the end, or both).