Initial implementation that allows query for similar resources

[Gozala]

Current draft does following:

• InputResource input type used by ingest(resource: InputResource!): Resource! mutation has being added an optional content: String field. If provided content will be indexed and saved in association with a resource url. Search for similar resources will query that index.
• scanner ingest all resources along with their contents, meaning they will be indexed. (Old data in the data base will have no index). ⚠️ Running scanner while server is running might corrupt index database
• new similar(input: String!): [Resource!]! similar(input: String!): SimilarResources! endpoint was added to the Query which can be used to query index for similar resources.~~

[Gozala]

@pvh I think we should land this piece. ksp-browser assumes these changes