Rank all mentities by the distance between name and both the mentity name and full name

Property definitions

nitc $ ModelIndex :: find_by_similarity
	# Rank all mentities by the distance between `name` and both the mentity name and full name
	fun find_by_similarity(name: String, filter: nullable ModelFilter): IndexMatches do
		var results = new IndexMatches
		results.add_all find_by_full_name_similarity(name, filter)
		results.add_all find_by_name_similarity(name, filter)
		return results
	end
src/model/model_index.nit:393,2--399,4