v0.30.0

feat: Support application-controlled session stickiness @abeluck (#95)

## what

this is a recreation of #60 without merge conflicts.

why

see #60 which this PR supersedes

references

• closes #60
• https://docs.aws.amazon.com/elasticloadbalancing/latest/classic/elb-sticky-sessions.html#enable-sticky-sessions-application
• https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/lb_target_group#stickiness