[aws] Add methods to handle missing ARNs/IDs

[anjafr]

Description

Introduces

• a method on AwsResource to construct the ARN of a resource instance.
• a static method on AwsResource to extract the ID from a given ARN

To-Dos

• [x] Add test coverage for new or updated functionality
• [x] Lint and test with tox
• [ ] Document new or updated functionality (someengineering/resoto.com#XXXX)

Code of Conduct

By submitting this pull request, I agree to follow the code of conduct.

[anjafr]

I wonder if it would be possible to create the arn for any AWS resource?

Technically: ... maybe - but practically it would require an enormous amount of contextual information that I don't think is feasible to gather here

[anjafr]

I wonder if it would be possible to create the arn for any AWS resource?

Technically: ... maybe - but practically it would require an enormous amount of contextual information that I don't think is feasible to gather here

@aquamatthias Did you have a chance to mull this over?

[aquamatthias]

So the TL;DR of our discussion: it is impossible to generate the ARN based on the information we already have. We need to handle this case manually in every service that does not report the ARN.