feat: Adapt Unity side to the new Archipelago realms system

[sandrade-dcl]

What does this PR change?

Fix #804

Layers are being deprecated inside the catalysts and will be replaced by the concept of island, which should be transparent for the unity-renderer. Determine which changes need to be done in order to assimilate this changes.

How to test the changes?

Test realms with the new Archipelago approach (ZONE)

1. Go to: https://play.decentraland.zone/index.html?renderer=urn:decentraland:off-chain:renderer-artifacts:feat/add-support-layerless-realm-unity-side&ENV=zone
2. Test the next features:

• JumpIn from "Explore & Play".
• JumpIn from "Friends".
• Online status in your friends.
• Users markers in the minimap.

Test realms with the old approach (ORG)

1. Go to: https://play.decentraland.zone/index.html?renderer=urn:decentraland:off-chain:renderer-artifacts:feat/add-support-layerless-realm-unity-side&ENV=org
2. Test the next features:

• JumpIn from "Explore & Play".
• JumpIn from "Friends".
• Online status in your friends.
• Users markers in the minimap.

Our Code Review Standards

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

[github-actions]

After the CI passes:

• This branch can be previewed at https://play.decentraland.zone/index.html?renderer=urn:decentraland:off-chain:renderer-artifacts:feat/add-support-layerless-realm-unity-side
• Code coverage report: https://renderer-artifacts.decentraland.org/branch-coverage/feat/add-support-layerless-realm-unity-side

[D4rWiNSS]

LGTM!