Problem Matchers: Higher scope for `message` property

Describe the enhancement
For the problem matchers, I have a special use case where an assertion in my code happens if some files are faulty. It would be pretty useful if I could match the message on the first pattern then loop through other lines to provide the files.

Maybe message property should be available in the pattern list but not necessarily for every object in pattern

Code Snippet

{
  "owner": "pytest",
  "pattern": [
    {
      "regexp": "^(FAILURE):\\s(.+)$",
      "message": 2
    },
    {
      "regexp": "^\\s+(.+)$",
      "file": 1,
      "loop": true
    }
  ]
}

Start with the problem matchers documentation linked in the issue and inspect the existing pattern schema and loop behavior. The issue names no implementation file or test; done should allow message on one pattern while subsequent lines provide files through looping.