Query rewrite for missing layer

[margaretha]

Kustvakt should add a layer when it is not specified/missing by using the default layer or based on the user-settings.

Query example in Poliqarp
contains(<s>, [tt/p=KOUS])

Serialization:

"query": {
    "@type": "koral:group",
    "frames": [
      "frames:isAround"
    ],
    "operands": [
      {
        "@type": "koral:span",
        "rewrites": [
          {
            "@type": "koral:rewrite",
            "operation": "operation:injection",
            "scope": "foundry",
            "src": "Kustvakt"
          }
        ],
        "wrap": {
          "@type": "koral:term",
          "foundry": "base",
          "key": "s"
        }
      },
      {
        "@type": "koral:token",
        "wrap": {
          "@type": "koral:term",
          "foundry": "tt",
          "key": "KOUS",
          "layer": "p",
          "match": "match:eq"
        }
      }
    ],
    "operation": "operation:position"
  }