fix: support multiple unreleased builder emote collections preview

[pravusjif]

WHY

Currently injecting more than 1 EMOTES unreleased collection through self-preview-builder-collections is not working.

WHAT

Refactored to have the builder emotes promise creation in a dedicated system so that several collections are supported

TEST INSTRUCTIONS

• To test you will need to create 2 COLLECTIONS in the emotes builder section of the marketplace at https://decentraland.org/builder/collections/
• Here I provide 4 test emotes that have to be loaded separately into both collections (put half in one and half in the other):
  • There is 1 emote that has audio (lovegrenadewithsound.zip), make sure to upload the .zip file directly so that it contains all the needed files
  • Put whatever emote details that you want (rarity, category, etc.)
  • test-emotes-props.zip
• Afterwards take note of their collection IDs which can be found in the URL of your collection, for example it looks like: 3062136a-065d-4d94-b28c-f57d6ef04860, make sure you are copying the COLLECTION id, not the ITEM ID from 1 specific item of the collection.

1. Download the build from this PR
2. Open the build with the self-preview-builder-collections app param injecting YOUR COLLECTION IDs separated by commas, example:
   MacOS
   open Decentraland.app --args --debug --position 100,100 --skip-version-check true --self-preview-builder-collections YOUR-COLLECTION-ID-1-GOES-HERE,YOUR-COLLECTION-ID-2-GOES-HERE
   WinOS
   "C:\Users\[YOUR-USER]\Downloads\Decentraland_windows64\Decentraland.exe" --debug --position 100,100 --skip-version-check true --self-preview-builder-collections YOUR-COLLECTION-ID-1-GOES-HERE,YOUR-COLLECTION-ID-2-GOES-HERE
3. After you enter the virtual world, confirm that when opening the Backpack you see the items from your collection and you can equip/unequip them (give them some time as they are raw GLTFs and may take longer to load).
4. Confirm that you can close the backpack and play the equipped emotes in your avatar outside the backpack too
5. Close the build and open it without the --self-preview-builder-collections parameter and confirm that normal emotes you own can be equipped and played with this PRs build
   MacOS
   open Decentraland.app --args --debug --position 100,100 --skip-version-check true
   WinOS
   "C:\Users\[YOUR-USER]\Downloads\Decentraland_windows64\Decentraland.exe" --debug --position 100,100 --skip-version-check true

[github-actions]

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

Name	Link
Commit	d9082e3
Logs	https://github.com/decentraland/unity-explorer/actions/runs/15570290676
Download Windows	https://github.com/decentraland/unity-explorer/suites/39916603348/artifacts/3300918246
Download Windows S3	https://explorer-artifacts.decentraland.org/@dcl/unity-explorer/branch/fix/multiple-builder-emotes-preview/pr-10234-d9082e3/Decentraland_windows64.zip
Download Mac	https://github.com/decentraland/unity-explorer/suites/39916603348/artifacts/3300884428
Download Mac S3	https://explorer-artifacts.decentraland.org/@dcl/unity-explorer/branch/fix/multiple-builder-emotes-preview/pr-10234-d9082e3/Decentraland_macos.zip
Built on	2025-06-10T22:46:38Z

[anicalbano]

✔️ Checked by QA following the indications of the PR:

WITH THE ARGS COLLECTION ID

10.06.2025_07.19.20_REC.mp4

WITHOUT THE ARGS

10.06.2025_07.22.01_REC.mp4

The emotes where checked and are working as expected!