Load world background images dynamically to reduce the initial Weavly dowload size

[sbates-idrc]

Initial work-in-progress implementation: https://github.com/sbates-idrc/c2lc-coding-environment/tree/C2LC-683

In our weekly C2LC meeting of 2023-01-10, we talked about the dynamic loading of backgrounds and decided to delay implementation of the dynamic loading until we hit a download size of 4MB.

Original Jira issue: https://fluidproject.atlassian.net/browse/C2LC-683