monitoring/commands: Move `AddCommentCommand' to `WithCommentCommand'

`AddCommentCommand' will be the command for adding both host and service comments.

refs #6593
monitoring/commands: Introduce `ObjectCommand' for commands that involve a Icinga object

refs #6593
monitoring/commands: Let `AddCommentCommand' be the command object for adding both host and service commands

refs #6593
monitoring: Fix typo in the `Downtime' data view
monitoring/commands: Move toggle instance feature commands into a single command

refs #6593
monitoring/commands: Add `DisableNotificationsExpireCommand'

refs #6593
monitoring/commands: Rename `DisableNotificationsCommandForm' to `DisableNotificationsExpireCommandForm'

The associated command also has 'Expired' in its name.

refs #6593
monitoring/commands: Move toggle instance feature command forms into a single form

refs #6593
monitoring/commands: Add object command classes

refs #6593
monitroing/commands: Remove method `CommandForm::inline()'

Inline forms will set themselves as inline.

refs #6593
monitoring/commands: Add object command forms

refs #6593