Using a HashSet instead of a List in the GetCategoryBreadCrumbAsync method

[skoshelev]

The cache getter in GetCategoryBreadCrumbAsync could be sped up significantly by using a HashSet instead of a List for keeping track of processed categories.

See details on this PR

[KaranChadha10]

@AndreiMaz @skoshelev I've created a PR (#7824) to address this issue. Please review when possible. Thanks!