Add options for affinity/tolerations in install helm chart

[ibot3]

The install helm chart for the operator currently does not offer configuration of pod tolerations and affinities:

https://github.com/CrunchyData/postgres-operator-examples/blob/main/helm/install/templates/manager.yaml

As these are very common Kubernetes concepts, they should be added to the chart.

[Mazorius]

If there is interest, I would like to create a PR to add node selection and tolerances

[dsessler7]

Thank you for your suggestion. We have a story in our backlog to add pod/node affinity configurations to the helm chart.

[Dan0x54]

I've opened a pull request for this if folks are interested - Added support for Affinity and Tolerations #304

[benjaminjb]

hey @Dan0x54 left a comment on the PR with (a) a bunch of my rambling to say that I'm OK with this change being Helm only but (b) a question about whether this addition should follow the if ... end style of adding potentially blank values. I'm curious what you think though obviously I lean towards that change to your PR. Thx!