Move all Context classes into Services

app/controllers/admin/projects_controller.rb

app/controllers/projects/blob_controller.rb

app/controllers/projects/edit_tree_controller.rb

app/controllers/projects/issues_controller.rb

app/controllers/projects/new_tree_controller.rb

app/controllers/projects/notes_controller.rb

app/controllers/projects_controller.rb

app/controllers/search_controller.rb

app/services/base_service.rb

app/services/files/base_service.rb

app/services/files/create_service.rb

app/services/files/delete_service.rb

app/services/files/update_service.rb

app/services/issues/bulk_update_service.rb

app/services/notes/create_service.rb

app/services/notes/load_service.rb

app/services/projects/create_service.rb

app/services/projects/fork_service.rb

app/services/projects/transfer_service.rb

app/services/projects/update_service.rb