[Core] Add Full text search

[yuripourre]

This will be very hard to do.

One way to do it is to have a separate collection with all the concepts condensed with attributes' names. So if we need to perform a full text search we can use this collection instead.

collection.createIndex("db_text", indexOptions(IndexType.Fulltext));
//To search
text("conceptID", "term");

The only downside of this approach is that each update should be applied to both collections.

References:
https://www.dizitart.org/nitrite-database/

[yuripourre]

Setting a custom TextEngine:

Nitrite db = Nitrite.builder()
        .filePath("/tmp/test.db")
        .textIndexingService(new MyTextIndexingEngine())
        .openOrCreate();