CMS-2680 Refactoring: Create SiteTemplateWizardPanel

 Move RichSelectedOptionView into own TS-file.
 CMS-2680 Refactoring: Create SiteTemplateWizardPanel

Added RichComboBoxBuilder to make RichComboBox more reusable.
 CMS-2680 Refactoring: Create SiteTemplateWizardPanel

 Rename item-selector class to rich-combobox
 CMS-2680 Refactoring: Create SiteTemplateWizardPanel

Created separate TS-files for each class in TemplateBrowseEvents and moved into a sub-module called "event. Same for SiteTemplateWizardEvents.
 CMS-2680 Refactoring: Create SiteTemplateWizardPanel

Moved each action in TemplateBrowseActions.ts into separate ts-files and moved into separate sub-module named "action".
 CMS-2680 Refactoring: Create SiteTemplateWizardPanel

Created separate TS-files for each class in SiteTemplateBrowseEvents and moved into a sub-module called "event".