Adds a multi-value intersection function to ES|QL.

Allows for an arbitrary number of two input sets, and returns a single output set of the values that intersect across all the sets. Each input set must be of the same datatype of multi-valued data.

Proposed design:

output_value_set = MV_INTERSECTION(set_1, set_2)

Example:

Given Set A = {"a","b","c"}; Set B = {"b","c","d"}; Set C = {"c", "d", "e"}; Set D = {"e"}

MV_INTERSECTION(A, B) -> {"b", "c"}
MV_INTERSECTION(C, B) -> {"c", "d"}
MV_INTERSECTION(A, D) -> { }