feat: update remote invoke context to actually invoke the executor

[mndeveci]

Updates RemoteInvokeContext object to invoke the remote invoke executor;

• Updated __enter__ method to find resource summary for given stack name and resource logical id
• Implemented run method, to instantiate remote invoke executor through its factory and run execute method on it
• Updated get_resource_summary in CFN utilities to return resources from nested stacks.

Mandatory Checklist

PRs will only be reviewed after checklist is complete

• Add input/output type hints to new functions/methods
• Write design document if needed (Do I need to write a design document?)
• Write/update unit tests
• Write/update integration tests
• Write/update functional tests if needed
• make pr passes
• make update-reproducible-reqs if dependencies were changed
• Write documentation

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[sriram-mv]

LGTM

[hnnasit]

Overall LGTM! Left a small comment.