Fixes #5088 #2524 - adding taxonomy related parameters to apidocs

- new param group `taxonomy` for taxable resources
- new param group `taxonomy_scope` for index actions of taxable resources
- pagination and search param moved to a group `search_and_pagination` to reduce duplicities
Why the extra `::`? Why `::Api::V2::BaseController` and not just `Api::V2::BaseController`?