Enable dynamic column aliases

[DictyosteliumDiscoideum]

Fixes #894.

Updates the parser to enable column aliases (i.e., "AS" statements) when columns are given in a dynamic array).

The syntax uses a nested array with two elements:

let columns = [];

if (view.field === "id") {
  columns.push("companies.id");
}

// ... other fields condition

if (view.field === "createdBy") {
  columns.push(["creator.email", "creatorEmail"]);
}
// columns = ["companies.id", ["creator.email", "creatorEmail"]]
sql`
  select
    ${sql(columns)}
  from
    companies
  join
    users as creator
  on
    companies."createdBy" = creator.id`

Which will produce:

SELECT "companies.id","creator.email" AS "creatorEmail"
FROM companies JOIN users as creator ON 
companies."createdBy" = creator.id

[DictyosteliumDiscoideum]

I fixed the typo that caused the checks to fail.