LSF automation should support heterogenous clusters

[sam-andaluri]

Currently worker nodes created as part of LSF schematics automation only supports a single flavor. Often we see customers requesting to create groups of nodes of different specifications. Apart from modifying the Terraform code there is no alternative to do this. Appreciate if you can consider enhancing to allow multiple worker node flavors. One suggestion here is to let customers create a csv file with worker node number and flavor and import that file into a Terraform variable.