Add config and tokenizer for query language Cypher

[tonilastre]

Language configuration and a tokenizer are created from the following Cypher (openCypher) resources:

• Cypher Query Language Reference (Version 9): https://opencypher.org/resources/

Contributing a new tokenizer / a new language

From CONTRIBUTING.md:

Please understand that we only bundle languages with the Monaco editor that have a significant relevance (for example, those that have an article in Wikipedia).

Here is the wiki: https://en.wikipedia.org/wiki/Cypher_(query_language)

Cypher is a declarative graph query language for graph databases. Cypher was largely an invention of Andrés Taylor while working for Neo4j, Inc. (formerly Neo Technology) in 2011. Cypher was originally intended to be used with the graph database Neo4j, but was opened up through the openCypher project in October 2015.

Usage

Cypher is being used and implemented in the following systems:

• Agens Graph: A multi-model database
• Amazon Neptune
• AnzoGraph: A native massively parallel (MPP) graph analytical database
• ArcadeDB
• CAPS: Cypher for Apache Spark
• Cypher for Gremlin
• Katana Graph
• Memgraph: An in-memory, transactional graph database
• Neo4j: A native, transactional property graph database
• RedisGraph: A graph module for Redis
• SAP HANA Graph
• Others...

[ghost]

All CLA requirements met.