Support Set as bind parameter

[tv42]

Is your feature request related to a problem? Please describe.

I tried to pass a Set as a bind parameter, expecting it to behave like Array. It was hard to debug since the query gave wrong results, not an error.

Describe the solution you'd like

Support Set just like Array: convert it to a Postgres array.

Additional context

Set:

$ deno eval 'import { Client } from "https://deno.land/x/postgres@v0.19.3/mod.ts"; const client = new Client({}); await client.connect(); const odds = new Set([1,3,5]); const result = await client.queryObject`SELECT 3=ANY(${odds}) AS should_be_true`; console.log(result.rows);'
[ { should_be_true: false } ]

Array:

$ deno eval 'import { Client } from "https://deno.land/x/postgres@v0.19.3/mod.ts"; const client = new Client({}); await client.connect(); const odds = new Array([1,3,5]); const result = await client.queryObject`SELECT 3=ANY(${odds}) AS should_be_true`; console.log(result.rows);'
[ { should_be_true: true } ]

[tv42]

This seems like a very simple change (but I haven't actually tested this):

https://github.com/denodrivers/postgres/blob/2606e50f02b525ac89012bbca9ed7ca863b215a9/query/encode.ts#L98-L99

add

  } else if (value instanceof Set) {
    return encodeArray(Array.from(value));