feat: Adding a method to get any object in a map by its unique ID

[kurtome]

Description

Adding a method to get any object in a map by its unique ID, map.objectById

Checklist

• [x] The title of my PR starts with a [Conventional Commit] prefix (fix:, feat:, docs: etc).
• [x] I have read the [Contributor Guide] and followed the process outlined for submitting PRs.
• [x] I have updated/added tests for ALL new/updated/fixed functionality.
• [x] I have updated/added relevant documentation in docs and added dartdoc comments with ///.
• [x] I have updated/added relevant examples in examples.

Breaking Change

• [ ] Yes, this is a breaking change.
• [x] No, this is not a breaking change.

[kurtome]

@spydon I think this is ready to merge 👍 , I don't have access on this repo