Refactor snippets finder & dont return internal snippets for external users

See merge request !2094

This reverts merge request !10845

TodoService should not call `.select(&:id)` on todos, because this is
bad performance. So instead use sub-queries, which will result in a
single SQL query to the database.

https://docs.gitlab.com/ee/development/sql.html#plucking-ids

ProjectsFinder should handle more options

Closes #28810

See merge request !9682

Extended ProjectFinder in order to handle the following options:
 - current_user - which user use
 - project_ids_relation: int[] - project ids to use
 - params:
   -  trending: boolean
   -  non_public: boolean
   -  starred: boolean
   -  sort: string
   -  visibility_level: int
   -  tags: string[]
   -  personal: boolean
   -  search: string
   -  non_archived: boolean

GroupProjectsFinder now inherits from ProjectsFinder.
Changed the code in order to use the new available options.

Fix for three open redirect vulns using redirect_to url_for(params.merge)))

See merge request !2082

This reverts merge request !10076

Speed up several project lists

See merge request !9903