Manage exported files
@type t() :: %Mobilizon.Export{ __meta__: term(), file_name: String.t() | nil, file_path: String.t(), file_size: integer() | nil, format: String.t(), id: term(), inserted_at: term(), reference: String.t(), type: String.t(), updated_at: term() }
@spec get_export(String.t(), String.t(), String.t()) :: t() | nil
@spec outdated(String.t(), String.t(), integer()) :: [t()]