Version 1.0.0

Refer to changelog for more details.

Backward incompatibility:

• getWidgetState and applyWidgetState include widget_row.
• The widget-states internal order changes.
• In FormDialog, the Ok button saves widget states and closes the dialog.
• In FormDialog, the Cancel button retrieves default states, or previously saved states,
  and closes the dialog.
• insertWidget is renamed insertWidgetToVerticalLayout.
  The current insertWidget inserts widgets in the form layout.
• Deprecates getWidgetStates to be getSavedWidgetStates.

More details:

• Adds user-defined functionalities for Ok and Cancel buttons in FormDialog.
• Adds default widget states upon inserting widgets to a form.
• Adds the class AdvancedDialogForm.
• Adds methods to insert widgets and remove widgets in the forms.
• Adds addSpanningWidget method to FormDockWidget.
• Adds several unit tests and examples.
• Removes _addWidget.
• Simplifies conda environment configuration for development.