high-available-webapps: configure ingress session affinity

[upgradingdave]

Ingresses should be configured to use sticky sessions when multiple instances of tasklist/operate/optimize are started.

Here's an example of annotations required to enable "cookie" based sticky sessions:

https://github.com/camunda-community-hub/camunda-8-helm-profiles/blob/main/tasklist/include/tasklist-ingress.tpl.yaml

If possible, it'd be good to enhance the makefile in the high-available-webapps profile to add these annotations.

cc: @ManuelDittmar