Load SQ from JSON

[juliangruendner]

It should be possible to load any structured query from a json file and pass it to the translator for testing.

First create a Reader for the Structured Query and then add the reader to all tests.

This will change existing tests like

https://github.com/num-codex/codex-sq2cql/blob/main/src/test/java/de/numcodex/sq2cql/TranslatorTest.java#L277-L280

where instead of building the structured query in java it should be read from a file, which should be put under:
src/test/resources

Example Input SQs can be generated using:
https://github.com/num-codex/codex-testdata-to-sq/tree/v0.2.0