Update e.set to accept an array of values and a type + prevent arrays from being spread into e.set

[jaclarke]

Current behaviour of e.set is buggy when spreading an array of values into it, since at runtime it's not possible to tell if an array was spread or the values were passed statically. This causes a mis-match in the cardinality determined statically by typescript and at runtime. If the array happens to be empty, it also causes a runtime error, as the type of the empty set cannot be determined. Eg:

const strs = ['abc']; // has type string[]

e.set(...strs); // ts infers cardinality as Many since 'strs' could have any length

e.set('abc'); // ts infers cardinality as One

// at runtime both above appear the same, so cardinality cannot be correctly determined for both

This PR prevents arrays from being spread into e.set (unless it's a tuple, eg. const strs = ['abc'] as const), and instead allows the array to be passed directly, along with a type expr, so the empty array case can be handled. The addition of a type arg also means it's no longer necessary to wrap each item of the array for non js primitive types:

const uuids: string[] = [/* some array of uuid strings */];

e.set(e.uuid, uuids);