Support creation of service accounts and default assignment

[brandtkeller]

Looking over the chart - I see the ability to assign a serviceAccount to pods based on the 'serviceAccountName` of each service.

What I would like to see is a default serviceAccount resource be available for creation - Example - and the assignment of that serviceAccount to the services that do not have serviceAccountName declared.

Summary:

• ServiceAccount.enabled defaulted to false and no serviceAccountName entries = same default state as is currently.
• ServiceAccount.enabled defaulted to true and no serviceAccountName entries = baseline service account for all services.
• ServiceAccount.enabled defaulted to true and a serviceAccountName entry on an individual service = baseline service account on all services except that individual service.

I believe this further encapsulates possible resources that should be created with the chart and those that could be integrated by overrides.

I'll do some testing around this concept and leave some more thoughts as I go - just wanted to get it written down such that others could review, and possibly indicate that not having the ability to create a baseline serviceAccount was explicitly by design.

[brandtkeller]

I did see mention in the changelog about the removal of a createServiceAccount from anchoreCatalog values. I believe this is different - because it would be more of a boolean enabled: <true/false> for a default service account.

@Btodhunter I'm open to any thoughts about why this may be something that the chart may not explicitly want to own.