feat: friend requests ui

[lorux0]

What does this PR change?

Integrates the friend requests UI so it can be shown whenever a friend request needs to be represented either by:

• send new
• cancel existent
• receive accept/reject

Here are some examples on how the UI can be displayed:

// Send new
await mvcManager.ShowAsync(FriendRequestController.IssueCommand(new FriendRequestParams
    {
        DestinationUser = new Web3Address("0xc9c29ab98e6bc42015985165a11153f564e9f8c2"),
    }), ct);

// Show existent
await mvcManager.ShowAsync(FriendRequestController.IssueCommand(new FriendRequestParams
    {
        Request = new FriendRequest(Guid.NewGuid().ToString(), DateTime.UtcNow,
            // One of these addresses should be our own user address
            "0x...",
            "0x...",
            "Custom Message"),
    }), ct);

How to test the changes?

1. Launch the explorer
2. Check that the startup flows works as expected

Our Code Review Standards

https://github.com/decentraland/unity-renderer/blob/master/docs/code-review-standards.md

[github-actions]

Windows and Mac build successfull in Unity Cloud! You can find a link to the downloadable artifact below.

Name	Link
Commit	85030d3
Logs	https://github.com/decentraland/unity-explorer/actions/runs/12917198747
Download Windows	https://github.com/decentraland/unity-explorer/suites/33396272584/artifacts/2471148990
Download Windows S3	https://explorer-artifacts.decentraland.org/@dcl/unity-explorer/branch/feat/friends/requests-ui/Decentraland_windows64.zip
Download Mac	https://github.com/decentraland/unity-explorer/suites/33396272584/artifacts/2471337304
Download Mac S3	https://explorer-artifacts.decentraland.org/@dcl/unity-explorer/branch/feat/friends/requests-ui/Decentraland_macos.zip
Built on	2025-01-22T22:59:43Z