feat: numeric aggregations

[SemyonSinchenko]

Any kind of Graph ML / Graph Embeddings will require to have something like:

1. Scalar functions
   a. l2_normalize(floatArrayColumn) -> floatArrayColumn
   b. random_vector() -> floatArrayColumn
2. Aggregate functions
   a. agg_float_array_sum
   b. agg_float_array_avg