ESQL: QueryBuilder dependency

[craigtaverner]

When developing lucene push-down optimizations within ES|QL we often need to make use of QueryBuilders, sometimes just using the existing ones in Elasticsearch, sometimes creating custom QueryBuilder implementations (like we did for spatial search in ST_INTERSECTS). But ES|QL does not need the full bells and whistles of Elasticsearch QueryBuilder. There are two concerns:

• Using existing QueryBuilder implementations connects us to implementations that have quite different purposes
• Creating custom QueryBuilder classes involves having to implement a bunch of methods that do nothing, which looks quite ugly

A first attempt to break this dependency was blocked by apparent needs for QueryBuilder in the QL code-base. Since we're decoupling ES|QL from the rest of QL, once that is done, this work should become much easier.

[elasticsearchmachine]

Pinging @elastic/es-analytical-engine (Team:Analytics)