[FEAT] Caching graph image url for 1 hr

[princedalsaniya]

Description of Changes:

Added URL Caching for Share Functionality:

• Caches the uploaded image URL in localStorage for 1 hour to reduce redundant API calls.
• Reuses the cached URL for sharing if the user triggers the share action within the 1-hour window.

Updated handleShareClick Logic:

• Checks for an existing cached URL before making a new API call to upload the chart image.
• If the cached URL is expired or unavailable, uploads a new image and updates the cache with the latest URL.

Improved User Experience:

• Prevents frequent uploads within a short time span and improves efficiency by reducing redundant network requests.