Improve performance on generating layers view

What does this MR do?

This resolves a concern from !58646 (merged) about caching / memoizing the groups once they've been looked up. I looked into the performance implication of Lodash's comparison in memoize to see if it was reasonable to use that rather than tracking updates ourselves and since it uses Map, it seemed reasonable.

Screenshots (strongly suggested)

No visual updates.

Does this MR meet the acceptance criteria?

Conformity

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Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.

Related to #327260 (closed)