Give the `Service` default port (5984) a name so that it is not ambiguous if `service.extraPorts` is used.

[samwho]

What this PR does / why we need it:

Sorry about this @willholley, but I noticed when trying to update to 4.5.4 and use my new extraPorts values that if you try to have multiple ports on a Service in Kubernetes, all ports need a name (https://github.com/kubernetes/kubernetes/issues/36803). If there's just one port, this name property is optional. Sadly this renders service.extraPorts useless in 4.5.4, so for 4.5.5 I've given the default port a name.

Checklist

[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.

• [x] Chart Version bumped
• [x] e2e tests pass
• [x] Variables are documented in the README.md (no new variables)
• [x] NEWS.md updated

[samwho]

Thank you so much for reviewing these PRs so quickly, we really appreciate it 🙏