Don't append `$ref` to the end of the object when dealing with `allOf` wrappers in `unnecessary_allof_ref_wrapper`

[jviotti]

Consider this schema:

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "allOf": [ { "$ref": "https://example.com" } ],
  "title": "Foo"
}

The unnecessary_allof_ref_wrapper linter rule will DELETE allOf and ASSIGN $ref, resulting in $ref getting AFTER allOf, like this:

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "Foo",
  "$ref": "https://example.com"
}

Whereas its cleaner to modify the allOf in place and end up with a schema like this:

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$ref": "https://example.com",
  "title": "Foo"
}

Another case is this schema:

{
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "allOf": [
      { "$ref": "https://example.com" },
      { "type": "string" }
    ],
    "title": "Foo"
}

Which will end up as:

{
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "allOf": [
      { "type": "string" }
    ],
    "title": "Foo",
    "$ref": "https://example.com",
}

Whereas ideally it ends up as:

{
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "$ref": "https://example.com",
    "allOf": [
      { "type": "string" }
    ],
    "title": "Foo"
}