Codify the minimum set of expectations for operators to "work well" (not break) with OLM's ecosystem

What makes for a well-behaved operator that works with OLM's current lifecycle ecosystem (e.g. packaging, update graphs, control logic idempotence, etc.).

A/C:

 - Collect wisdom from SDK and PE
 -  Expectations defined
 - Update best-practices documentation for OLM
 - Docs reviewed by: PE, SDK, and DOCS

Current best practices documentation:

https://olm.operatorframework.io/docs/best-practices/common/

E.g. If you need to change labels in a Deployment PodSpec between versions of the operator, you need to rename your deployment.