message: Update addTheme to bkank page composition name
diff: "$schema": "http://json.schemastore.org/template",
  "author": "Microsoft",
  "classifications": ["Universal"],
  - "name": "wts.Project.RN.Tabbed.AddThemeToPage",
  - "shortName": "wts.Project.RN.Tabbed.AddThemeToPage",
  - "identity": "wts.Project.RN.Tabbed.AddThemeToPage",
  + "name": "wts.Page.RN.Blank.AddTheme",
  + "shortName": "wts.Page.RN.Blank.AddTheme",
  + "identity": "wts.Page.RN.Blank.AddTheme",
  "tags": {
  "language": "Any",
  "type": "item",
  