Add container of operations on packages by their NEVRAs.
Remove unneeded sack parameter from open_history.
Return history of a transaction in the new container.
refactor: Rename functions in Base.history_undo.
refactor: Move obsoleted packages handling within Base.history_undo.
refactor: Move the content of HistoryCommand._hcmd_undo to BaseCli.history_undo_transaction.
refactor: Rename Base.history_undo to Base.history_undo_operations.
refactor: Move the content of HistoryCommand._hcmd_rollback to BaseCli.history_rollback_transaction.
Fix AttributeError raised when BaseCli.history_rollback_transaction called.