This optimises how GroupProjectsFinder builds it collection, producing
simpler and faster queries in the process. It also cleans up the code a
bit to make it easier to understand.
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.
