Add option to set boot disk size when creating AWS Batch CE using Forge

[robsyme]

When creating an AWS Batch CE using Seqera Platform, there is an option to set both the EBS blocksize and also the boot disk size:

The CLI offers an argument to set the ebs blocksize, but there is no argument for boot disk size:

--ebs-blocksize=<ebsBlockSize>             This field controls the initial size of the EBS auto-expandable volume. New blocks of the same size are added
                                             as necessary when the volume is running out of free space [default: 50 GB].