feat(api-gw): add API-Gateway construct

[krissrex]

This will create HTTP APIs using an integration for either:
lambda, sqs, alb.

The API can use auth of either: none, auth basic, IAM.

The API will get a custom domain, certificate and dns routes set up for it,
and access logs with a custom log format.

Note that the lambda integration is not thorougly tested in production.
The other integrations are well tested.

The file is a bit big. I could extract some of the sub-constructs to separate files, as long as it doesnt break encapsulation/isolation.
I don't want them exported out.

[krissrex]

Potential improvements:

1. Move Basic-Auth Lambda code to an asset js-file, instead of inline string.
2. Split up the file in one file per construct, while not exporing out the private constructs. Maybe I need a _MyPrivateConstruct like naming schema, or just live with the stacks exported by exact file-path (@liflig/cdk/apigateway/privateStack) and not inside index.ts for apigateway.
3. sub-package/namespace the apigateway to http to indicate that it is not a REST API-GW?
4. Allow several API-GW to use the same custom domain but different routes, by sharing custom domain (and API-GW)?