Create the initial UI of Maps panel in TemplateData GUI in ext.TemplateDataGenerator.ui.tdDialog.js
Acceptance criteria:
- There is a panel for viewing the maps object
- The maps object is displayed in JSON format at first, in a disabled text widget. It is not editable for now.
- There is a button in the main panel, which opens the maps panel
- There is a button to navigate away from the maps panel