Add source to QueryReferenceRewrite

[margaretha]

QueryReferenceRewrite rewrites a reference to a stored query, e.g.

{
  "ref" : "dory/dory-q",
  "@type" : "koral:queryRef"
}

is rewritten into

{
  "@type" : "koral:token",
  "rewrites" : [ {
    "@type" : "koral:rewrite",
    "src" : "Kustvakt",
    "origin" : "Kustvakt",
    "operation" : "operation:deletion",
    "scope" : "@type(koral:queryRef)"
  }, {
    "@type" : "koral:rewrite",
    "src" : "Kustvakt",
    "origin" : "Kustvakt",
    "operation" : "operation:deletion",
    "scope" : "ref(dory/dory-q)"
  }, {
    "@type" : "koral:rewrite",
    "src" : "Kustvakt",
    "origin" : "Kustvakt",
    "operation" : "operation:injection"
  } ]
}

The scope should be updated and source should be added as follows

{
  "@type" : "koral:token",
  "rewrites" : [ {
    "@type" : "koral:rewrite",
    "src" : "Kustvakt",
    "origin" : "Kustvakt",
    "operation" : "operation:deletion",
    "scope" : "@type",
    "source" : "koral:queryRef"
  }, {
    "@type" : "koral:rewrite",
    "src" : "Kustvakt",
    "origin" : "Kustvakt",
    "operation" : "operation:deletion",
    "scope" : "ref",
    "source" : "dory/dory-q"
  }, 
  ...
 ]
}

[margaretha]

To be coherent with VirtualCorpus(Reference)Rewrite, operation:override should also be used in QueryReferenceRewrite instead of deletion and injection.