* Add modelId and modelText to KnnVectorQueryBuilder
Use QueryVectorBuilder within KnnVectorQueryBuilder to make it
possible to perform knn queries also when a query vector is not
immediately available. Supplying a text_embedding query_vector_builder
with model_text and model_id instead of the query_vector will result
in the generation of a query_vector by calling inference on the
specified model_id with the supplied model_text (during query
rewrite). This is consistent with the way query vectors are built
from model_id / model_text in KnnSearchBuilder (DFS phase).
