multi-valued equality expressions in Optic builder

[ehennum]

Currently, the Optic builder supports exactly two values in an equality expression.

Equality of a set of values can be expressed with AND relations over equality pairs, but such syntax is verbose and requires knowing the number of values in advance (or generating the entire expression).

Per internal task 47546, the Optic builder should support two or more values in an equality expression.

While generating the new interface, also fix the internal bug 54922 on the link for the param() JavaDoc.

[ehennum]

Assigning for awareness in case of regression. The unit tests should provide sufficient coverage of the increased cardinality on the arguments to the eq() operator.