Page XML Validator

[ollietb]

DX: It would be nice to have a way of finding errors with the page XML files. Our developers regularly make mistakes with the XML settings which have to be debugged using the web inspector, which isn't ideal and sometimes the errors don't show. Examples of things which can be checked are:

• The key is unique
• That the template exists and can be found
• The controller exists
• Default block types exists
  ..etc..

Also during development the names, structure and types of nodes change regularly which can also cause issues without any error messages, so maybe the XML validator could also check that the data matches the structure and show error messages if it doesn't?