fix types to use module augmentation instead of @ts-ignore

[andyjy]

Hi @pffigueiredo - this PR shows how to use module type augmentation to prevent the requirement for @ts-ignore throughout.

Just a suggestion - perhaps not huge benefit given the need to add (+ maintain?!) more detailed type declarations for the pg internals.

But it can bring some benefits e.g. exposes the actual type of types: CustomTypesConfig where it was previously any

[andyjy]

@jawj would you like me to update this PR for the refactor that just landed?

If not then it can be closed - was just a few extra minutes work while working on a previous issue. I'd suggest on balance it's probably worth the additional type safety but fair to consider it mostly a stylistic choice for y'all.

[jawj]

Hi @andyjy. Yes, please do update in the light of the refactor, and thanks for doing this. It's a definite improvement! :)