Add variable to support specifying version of helm chart used

[azalenski-branch]

Hello :)

Can you please add support for a variable (or multiple) that will allow user to select the version of helm chart that should be used for components like agent, controller, evictor and spot_handler? This will allow users to:

1. Control the versions they want to use, instead of always using the latest.
2. Perform the upgrade of version used as by default helm won't upgrade the version if it's not explicitly set.

Here's the documentation for version parameter inside helm_release Terraform resource: https://registry.terraform.io/providers/hashicorp/helm/latest/docs/resources/release#version

[calebAtIspot]

Looks like this got added back in #34

[calebAtIspot]

Actually, it got added back but there is still a ignore_changes lifecycle for version :|