Allow optional security_groups to be passed to batch instance

[aimran-adroll]

Personally I would benefit from having user supplied optional security_groups in addition to the one generated by the module.

My org has existing SGs that we typically attach to new infra to allow access to common services (e.g RDS, presto clusters etc)

[delagoya]

Looks like the PR above added the metaflow-computation module compute_environment_additional_security_group_ids input variable.

This issue should be closed.