Validate tag version during deployment

[nbeloglazov]

Deploy command is bin/deploy --tag=version. The version is not validated by script. It's propagated to fargate as it is and only there, if it's invalid, task will fail deployment. Deployment should fail earlier if version is incorrect and provide better message. Additionally we should handle different formats of version. Currently civiform has releases v1.7.0 so users need to provide --tag=v1.7.0. It's reasonable that users provide --tag=1.7.0 (note missing v) which should also be supported.