* When category ids in the indexer are "strings" we create a unique hash to make it compatible with Torznab
* This PR also fix several issues related to custom cats
* Core: Categories are stored in a real tree
* Sorting: First Torznab categories sorted by Id and then custom cats sorted by Name
* Filtering: Results with child category are not removed when searching by parent category. Details in #8049
* Jacket UI: Add parent category when at least one child category exists
* Torznab (caps): Remove non existent children categories. Remove duplicated categories. Details in #10006
Diego Heras