fix: Fix rpdk configs for new cloudformation cli versions

[maastha]

Proposed changes

Jira ticket: CLOUDP-220385

This PR updates import path setting in rpdk config of various resources to support newer versions of cloudformation-cli-go-plugin as per aws-cloudformation/cloudformation-cli#1054 (comment)

EDIT (Agustin): As a followup to this draft pull request, I was able to identifying missing changes in the .rpdk-config files and verified the change by creating a stack after publishing a private resource with the latest config changes. Used the following examples project as reference: https://github.com/aws-cloudformation/cloudformation-cli-go-plugin/tree/master/examples/github-repo
This PR will unblock us from developing with latest cloudformation cli versions, which in turn is also used in our publishing workflow.

Type of change:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as
  expected)
• This change requires a documentation update

Manual QA performed:

• cfn invoke for each of CRUDL/cfn test
• Updated resource in example
• Published to AWS private registry
• Used the template in example to create and update a stack in AWS
• Deleted stack to ensure resources are deleted
• Created multiple resources in same stack
• Validated in Atlas UI
• Included screenshots

Required Checklist:

• I have signed the MongoDB CLA
• I have added tests that prove my fix is effective or that my feature works
• I have checked that this change does not generate any credentials and that they are NOT accidentally logged anywhere.
• I have added any necessary documentation (if appropriate)
• I have run make fmt and formatted my code
• For CFN Resources: I have released by changes in the private registry and proved by change
  works in Atlas

Further comments

[maastha]

updating to work with latest versions of cloudformation-cli-go-plugin as per aws-cloudformation/cloudformation-cli#1053 (comment)
Currently this is resulting in errors when trying to submit resource to private registry and manually creating a stack [Lambda function handler threw an uncaught exception: fork/exec /var/task/handler: no such file or directory]

[AgustinBettati]

I was able to reproduce this error. As a follow-up change I also had to adjust entrypoint and testEntrypoint in .rpdk-config file to bootstrap and this way I was able to submit a resource to the private registry and create a stack successfully.

[lantoli]

not changed in this PR but in case you can do it here, all ldXflagsD (debug) must not have -s -w, an example would be:

ldXflagsD=-X github.com/mongodb/mongodbatlas-cloudformation-resources/util.defaultLogLevel=debug -X github.com/mongodb/mongodbatlas-cloudformation-resources/version.Version=${CFNREP_GIT_SHA}

[AgustinBettati]

thanks for suggestion, adjusted.

[lantoli]

can we add/change some doc with the expected cfn cli versions?