feat(gateway):dedicated error type for denylists

[shobit000]

This pull request addresses issue #591 by introducing a dedicated error type for denylists in the IPFS gateway. The changes ensure that blocked content errors are properly conveyed using a specific error type instead of relying on string-based error checking.

Changes Made

1. Introduced BlockedError type
2. Updated isErrContentBlocked function
3. Updated webError function

[welcome]

Thank you for submitting this PR!
A maintainer will be here shortly to review it.
We are super grateful, but we are also overloaded! Help us by making sure that:

• The context for this PR is clear, with relevant discussion, decisions
  and stakeholders linked/mentioned.

• Your contribution itself is clear (code comments, self-review for the
  rest) and in its best form. Follow the code contribution
  guidelines
  if they apply.

Getting other community members to do a review would be great help too on complex PRs (you can ask in the chats/forums). If you are unsure about something, just leave us a comment.
Next steps:

• A maintainer will triage and assign priority to this PR, commenting on
  any missing things and potentially assigning a reviewer for high
  priority items.

• The PR gets reviews, discussed and approvals as needed.

• The PR is merged by maintainers when it has been approved and comments addressed.

We currently aim to provide initial feedback/triaging within two business days. Please keep an eye on any labelling actions, as these will indicate priorities and status of your contribution.
We are very grateful for your contribution!

[lidel]

@shobit000 thank you for opening this, but was this generated with AI?

Same concerns as in

• feat(gateway): introduce typed errors for blocked content #855 (comment) – who will produce this error?
• feat(gateway): introduce typed errors for blocked content #855 (comment) default to 410, no need for extra flag, nobody will default to "legal reasons".

[shobit000]

yeag , used ai but will definately update you on my work on this pr

[gammazero]

The information on the reason for being blocked needs to come from nopfs as it gives more context for the appropriate error to return. We need a solution that takes this into account. Closing, as this and not the way we want to solve this.