fix(DataTable): debounce global filter in Customers demo to improve performance

[Coderxrohan]

Problem

Typing in the global filter of the Customers DataTable demo causes noticeable lag when row count is increased (e.g. 50+ rows), as filters are updated on every keystroke, triggering full table re-renders.

Solution

Applied useDebounce to the global filter input and moved filter updates into a debounced effect so filtering only runs after typing pauses.

Impact

• Smooth typing for larger datasets
• No behavior change to filtering logic
• Demo now reflects recommended performance best practices

Testing

• Verified locally with 50+ rows
• Confirmed reduced re-renders using React Profiler

Fixes: #8460 (DataTable demo: noticeable lag and whole-table re-renders when increasing rows (demo reproduction))