[feature request] Add IPv6 support on pl-diagnose.on.fleek.co

[SmaugPool]

It would be nice to have IPv6 support on https://pl-diagnose.on.fleek.co/ page.
Currently "network is unreachable" error is returned when trying to reach IPv6 multi-addresses which could let think that there is an issue with the node.

For example:

• what I tried to do: connecting to one advertised IPv6 address of my node
• url of the page: https://pl-diagnose.on.fleek.co/#/diagnose/access-content?addr=%2Fip6%2F2a01%3A4f9%3A1a%3A9169%3A%3A2%2Fudp%2F4001%2Fquic%2Fp2p%2F12D3KooWQBuVUAsnWzfgbe4pgjdSRB9bEnWWDtzvcC5dh2qBepxj&backend=https%3A%2F%2Fpl-diagnose.onrender.com&cid=%2Fp2p%2F12D3KooWQBuVUAsnWzfgbe4pgjdSRB9bEnWWDtzvcC5dh2qBepxj
• what I got:

An error occuredThe backend couldn't reach out to your node. It failed with the following error: failed to dial 12D3KooWQBuVUAsnWzfgbe4pgjdSRB9bEnWWDtzvcC5dh2qBepxj:

• [/ip6/2a01:4f9:1a:9169::2/udp/4001/quic] INTERNAL_ERROR: write udp6 [::]:60212->[2a01:4f9:1a:9169::2]:4001: sendto: network is unreachableOur backend node couldn't reach this peer.Troubleshooting Steps:Solution 1solution 1 step Asolution 1 step BSolution 2solution 2 step Asolution 2 step B

Details:

• title: An error occured
• issueRef: node availability
• rawData:

{
  "error": null,
  "data": {
    "id": "12D3KooWQBuVUAsnWzfgbe4pgjdSRB9bEnWWDtzvcC5dh2qBepxj",
    "connectToPeerError": "failed to dial 12D3KooWQBuVUAsnWzfgbe4pgjdSRB9bEnWWDtzvcC5dh2qBepxj:\n  * [/ip6/2a01:4f9:1a:9169::2/udp/4001/quic] INTERNAL_ERROR: write udp6 [::]:60212->[2a01:4f9:1a:9169::2]:4001: sendto: network is unreachable"
  }
}