CLI for parsers, transformers and generators

[jitsedesmet]

A CLI can help others interact with Traqula from within their own workflow. This can mean checking the validity of a query from within a terminal, but also allowing other software to invoke Traqula though a separate process and parsing JSON output.
This feature depends on the fact that Traqula's algebra and AST components are simple DTOs and therefore completely serializable (good job belly feeling).

Creating a binary and installing it to the system is as easy as adding a "bin" key to package.json (see Comunica), and adding a CLI parser, which many packages can help us with.

[jitsedesmet]

1. For engines/parser-sparql-1-1 and engines/parsers-sparql-1-2 we should look at the CLI options supported by the Parser exposed in https://github.com/RubenVerborgh/SPARQL.js/
2. 1. For engines/generator-sparql-1-1 and engines/generator-sparql-1-2 we should look at the CLI options supported by the Generator exposed in https://github.com/RubenVerborgh/SPARQL.js/
3. For engines/algebra-sparql-1-1 and engines/algebra-sparql-1-2 we should look at the CLI options supported by https://github.com/joachimvh/SPARQLAlgebra.js

Needless to say, support should reflect the design choices of Traqula and not blindly be copied from those projects. Especially taking care of the modularity Traqula provides, therefore, if necessary, a new package should be created under the package directory facilitating the creation of CLIs that are related to traqula's core package (@traqula/core).