GCP Batch resource deployment UX improvements

[araghukas]

See here for notes.

• The following infra defaults are not used for resource creation

bucket_name
container_image_uri
service_account_email
vcpus
memory
time_limit
poll_freq
retries
cache_dir
access_token

• The key_path variables is NOT required, it has a default value

• Some missing defaults could be specified in the help menu. For example, region defaults to "us-east1"

• The parameter named vcpus here is named vcpu in AWS Batch. Neither should be an infra parameter, else names should be resolved.

• The prefix parameter is used as a suffix.

### Tasks
- [ ] Review infra defaults NOT used for resource creation
- [ ] Update `key_path` so that default is displayed and is listed as not required
- [ ] Populate defaults/effective defaults for visibility in help menu
- [ ] Use `prefix` as a prefix or rename to `suffix`