Shared API Gateway support for HTTP Endpoints

[vlewin]

This is a Feature Proposal

Please add support for Shared API Gateway

Description

• Add shared api gateway support
• No config required

Additional Data

• Serverless Framework Core Version you're using: 1.28.0
• The Plugin Version you're using: latest
• Operating System: Mac OS X

[vlewin]

Working but not fully tested adaptations: master...vlewin:master

Tested with my demo project. API endpoint was properly attached to restApiId/restApiRootResourceId

[horike37]

Hi @vlewin
Thank you for the proposal! That's a great idea!
Could you send a PR with current working status so that we can test and review?