internal-ci: Support multiple applications and platforms

- Hardcoded inputs are replaced by configruable parameters
to allow using the same code for building multiple
applications on different targets without the need
to duplicate codes.

- Fix S3 bucket emptying in cleanup where the script can now
be used to clean up all resources as opposed to just the
resources associated with the aws-iot-example application.

Signed-off-by: Ahmed Ismail <Ahmed.Ismail@arm.com>