Add IsDefault and IsCancel for all dialog buttons

DiscordChatExporter.Gui/Views/ErrorDialog.ammy

@@ -19,6 +19,8 @@ UserControl "DiscordChatExporter.Gui.Views.ErrorDialog" {
       Command: DialogHost.CloseDialogCommand
       Content: "OK"
       HorizontalAlignment: Right
+      IsDefault: true
+      IsCancel: true
       Style: resource dyn "MaterialDesignFlatButton"
     }
   }

DiscordChatExporter.Gui/Views/ExportDoneDialog.ammy

@@ -22,7 +22,8 @@ UserControl "DiscordChatExporter.Gui.Views.ExportDoneDialog" {
         Margin: 8
         Click: OpenButton_Click
         Command: bind OpenCommand
-        Content: "OPEN IT"
+        Content: "OPEN"
+        IsDefault: true
         Style: resource dyn "MaterialDesignFlatButton"
       }
 
@@ -31,6 +32,7 @@ UserControl "DiscordChatExporter.Gui.Views.ExportDoneDialog" {
         Margin: 8
         Command: DialogHost.CloseDialogCommand
         Content: "DISMISS"
+        IsCancel: true
         Style: resource dyn "MaterialDesignFlatButton"
       }
     }

DiscordChatExporter.Gui/Views/ExportSetupDialog.ammy

@@ -81,6 +81,7 @@ UserControl "DiscordChatExporter.Gui.Views.ExportSetupDialog" {
         Margin: 8
         Command: DialogHost.CloseDialogCommand
         Content: "CANCEL"
+        IsCancel: true
         Style: resource dyn "MaterialDesignFlatButton"
       }
     }

DiscordChatExporter.Gui/Views/SettingsDialog.ammy

@@ -27,6 +27,8 @@ UserControl "DiscordChatExporter.Gui.Views.SettingsDialog" {
       Command: DialogHost.CloseDialogCommand
       Content: "SAVE"
       HorizontalAlignment: Right
+      IsDefault: true
+      IsCancel: true
       Style: resource dyn "MaterialDesignFlatButton"
     }
   }