Refactor dialog Fxml files to their base fxml template

[Daytron]

Since header style background can be interchangeable, there's no need to keep redundant dialog fxml files. Instead refactor them to their base template dialog fxml such as:

• OK dialog
• OK CANCEL dialog
• YES NO dialog
• Input text dialog and
• Exception dialog

Refactor includes:

• DialogType will served as dialog fxml path enum
  • move DialogType.java to ../dialog/ package
  • delete Fxml.java
  • add private constructor with fxml path as parameter
  • add a protected getPath() method so that Dialog will only have access to the values
• Refactor fxml files to their base template
• Remove redundant fxml files such as:
  • WarningDialog
  • ConfirmationDialog
  • InformationDialog
  • WarningDialog
  • All generic dialogs
• Rename applyHeaderColorStyle(HeaderColorStyle headerColorStyle) to setHeaderColorStyle(HeaderColorStyle headerColorStyle) and set it to public final
• Remove previous setHeaderColorStyle(HeaderColorStyle headerColorStyle)
• Update the new setHeaderColorStyle(HeaderColorStyle headerColorStyle) for default and custom style background
• Refactor constructor with fxml file loading using DialogType instead of Fxml enum
• Add updateHeaderColorStyle(HeaderColorStyle headerColorStyle) method for easy style color switching for setHeaderColorStyle(HeaderColorStyle headerColorStyle)
• Define a default background color (WHITE) for the dialog's header if CUSTOM style is selected in the constructor (this will keep the drop shadow effect for the header in play, otherwise the effect is applied to the text if no background is applied). Let user apply their own custom style via setCustomHeaderColorStyle(String colorStyle) later on.