fix: replace generated Image template with Studio Pro extraction

The hand-generated template used wrong field names (Description vs
WidgetDescription, IsPluginWidget vs WidgetPluginWidget, etc.) and
was missing system properties (Name, Visibility), causing CE0463
"widget definition changed" and CE0572 errors.

Replace with a real extraction from test3.mpr (Mendix 11.8.0) where
the Image widget was created and validated in Studio Pro.

Also add Image widget to mxcli extract-templates command for future
re-extraction.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ako

cmd/mxcli/cmd_extract_templates.go

@@ -81,6 +81,7 @@ func runExtractTemplates(cmd *cobra.Command, args []string) error {
 		{"com.mendix.widget.web.datagriddatefilter.DatagridDateFilter", "datagrid-date-filter.json", "Date filter"},
 		{"com.mendix.widget.web.datagriddropdownfilter.DatagridDropdownFilter", "datagrid-dropdown-filter.json", "Dropdown filter"},
 		{"com.mendix.widget.web.datagridnumberfilter.DatagridNumberFilter", "datagrid-number-filter.json", "Number filter"},
+		{"com.mendix.widget.web.image.Image", "image.json", "Image"},
 	}
 
 	extracted := 0