Call Edit to permit editing of the active record in a dataset. Edit determines the
current state of the dataset. If the dataset is empty, Edit calls Insert.
Otherwise Edit:
Calls CheckBrowseMode to post any pending changes to a prior record if necessary.
Calls the BeforeEdit event handler.
Retrieves the record.
Puts the dataset into dsEdit state, enabling the application or user to modify fields in
the record.
Broadcasts the state change to associated controls.
