Persisted query provider 'JsonQueryMapQueryProvider' not working.

I have been investigating persisted queries and it seems that if you are using JsonQueryMapQueryProvider it is broken. [JsonQueryMapQueryProvider.php#L56](https://github.com/drupal-graphql/graphql/blob/65a6555daaf1a7e3df3e2c2ed5b1d76a13f804d3/src/GraphQL/QueryProvider/JsonQueryMapQueryProvider.php#L56)

```
if (isset($versions) && isset($versions[$version]) && file_exists($versions[$version])) {
$contents = json_decode(file_get_contents($versions[$version]), TRUE);
if ($query = array_search($id, $contents)) {
return $query;
}
}
```

uses an `array_aearch()` to locate the id in the json array and then returns the result, which is not a query, and also being an `array_search()` if the index returned is 0 then it jumps to the returning NULL.

I played a little and changed it to the following which got it working.

```
if (isset($versions) && isset($versions[$version]) && file_exists($versions[$version])) {
$contents = json_decode(file_get_contents($versions[$version]), TRUE);
if (isset($contents[$id])) {
return $contents[$id];
}
}
```

Which this works however I am not sure why this is being done like this, as we are just setting up a json array with the query in it, and once deployed you can't change the query as the sha1 will change.

I am wondering if a GQL query provider would work better, Instead of a JSON file with the query, use a text file with extension of `.gql` which is a plain text version of the query which is a lot easier to read and edit. As for using a sha1 to reference the query just using the filename (excluding the extension) which will mean the query can be changed without needing to change the frontend references to this query.