Fix: Support PGSQL Decimal type

[jarekcieslak]

I've noticed that DB schemas containing fields defined as DECIMAL generate types as strings. Here's an example:

CREATE TABLE booking_pricing
(
    id     INT NOT NULL GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
    total_price            DECIMAL(15,4)           NOT NULL,
)

produces:

export type BookingPricing = {
  id: number;
  total_price: string;
};

instead of :

export type BookingPricing = {
  id: number;
  total_price: number;
};

[koistya]

@jarekcieslak by default knex / pg-types returns decimal/numeric values as strings I believe; if you need them to be numeric instead, in addition to overriding generated data type, you would also need to tweak pg-types settings:

https://github.com/brianc/node-pg-types