feat: Gracefully fetch external json

[AlexV525]

Changes

The uri field could be empty for some of the tokens, for example, USDC (6GpMXZmS7bBHBc9TrVRFUaerSQXYJPkpq31aET3UWd4R).

{
  "name": "USD Coin",
  "symbol": "USDC",
  "uri": "",
  "updateAuthority": "2wmVCSfPxGPjrnMMn7rchp4uaeoTqN39mXFC2zhPdri9",
  "mint": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v"
}

The change will make sure to request a valid URI or return the null result rather than throws.

Checklist

• PR is ready for review (if not, it should be a draft).
• PR title follows Conventional Commits guidelines.
• Screenshots/video added.
• Tests added.
• Self-review done.