Improve typings comparing to the original SDK version

[just-boris]

Describe the problem underlying the enhancement request

There is a known issue on AWS SDK v3 typings: aws/aws-sdk-js-v3#1613

Marking everything as possibly undefined undermines the whole point of typings in the first place.

Since this package tries to reuse the upstream type definitions, it is suffering from the same issue too.

Describe the solution you'd like (if any)

The aws-lite project could provide enhanced typings for the most common use-cases

Describe alternative solutions you've considered

For now I am just using non-null assertion ! everywhere

Additional context or notes

This is not much of a feature request, more like a suggestion for to take an opportunity

[ryanblock]

Thank you – I don't really use types, so this is pretty interesting to learn. Unfortunately, I'm not super surprised.

For aws-lite, I decided to add @aws-lite/*-types package support as an easy(ish) win to ease the transition from SDK v3 and help folks get comprehensive types without being a huge burden on us during the early days of this project. AWS has (or had?) dozens of developers working on the JS SDK; right now aws-lite has, um, me and @tbeseda! 😅

As such, I think attempting to maintain our own types is currently out of scope. However, as the project grows I could see this as being something we take on eventually, especially if AWS teams and outside contributors begin to help us maintain them.