Gather issuable metadata to avoid n+ queries on index view

app/controllers/concerns/issuable_collections.rb

app/controllers/concerns/issues_action.rb

app/controllers/concerns/merge_requests_action.rb

app/controllers/projects/issues_controller.rb

app/controllers/projects/merge_requests_controller.rb

app/models/award_emoji.rb

app/models/concerns/issuable.rb

app/models/note.rb

app/views/projects/issues/_issue.html.haml

app/views/projects/merge_requests/_merge_request.html.haml

app/views/shared/_issuable_meta_data.html.haml

changelogs/unreleased/issue_25900.yml

spec/controllers/dashboard_controller_spec.rb

spec/controllers/projects/issues_controller_spec.rb

spec/controllers/projects/merge_requests_controller_spec.rb

spec/features/issuables/issuable_list_spec.rb

spec/support/issuables_list_metadata_shared_examples.rb