set up individual secrets for what used to be HCPConfig secret

[jmurret]

NOTE: At first glance this looks huge, but its really because the same sets of bats tests and helm failure logic are in multiple files to check that for each secret, if one of the secretName or the secretKey is set, then both are set. Besides this, this actually a very small change.

Motivation:

• the question of whether or not each of these environment variables needs to be individually configured in the helm chart was first posed by Iryna in my original PR
• there are 6 six environment variables that canbe set for the hcpsdk. 3 are required and 3 are optional. in order to make the setting of these environment variables optional in server-statefulset, they need to be individual helm values so that the system can check whether they are nil or not.
• this change replaces what consul-k8s CLI - hcp self-managed clusters - fix the required environment variables that should just default to production settings #1593 tried to do bu did notwork (described below).
• the current method of trying to allow the environment variable to read a null key from a secret without any conditional logic such as below errors on the pod during startup and therefor still causes the user to set all 6 environment variables when using the CLI.

              valueFrom:
                secretKeyRef:
                  name: {{ .Values.global.cloud.secretName }}
                  key: scada-address 

Changes proposed in this PR:

• make all 6 of the environment variable their own configurable helm chart value
• conditionally set the 3 optional ones in server-statefulset based on the presence of a value
• conditionally set them in the CLI preset values for cloud preset based on the presence of a value when the user runs the CLI
• add helm check for the 3 required values when global.cloud.enabled=true
• add helm check for all 6 six secrets so that when either the secretName or secretValue is provided, both are provided

How I've tested this PR:

• unit / acceptance tests
• manually

How I expect reviewers to test this PR:
👀

Checklist:

• Tests added
• CHANGELOG entry added

  HashiCorp engineers only, community PRs should not add a changelog entry.
  Entries should use present tense (e.g. Add support for...)

[jmurret]

changed name. this used to be one secret with 6 six keys (3 required and 3 optional). Now there are 6 secrets for more flexibility and the ability to allow optional values.

[jmurret]

This simply checks all 6 secrets so that if either secretName or secretKey are provided, then both are provided.

[jmurret]

got rid of the small helper functions like saveBootstrapTokenSecret() because they really did not do much and I moved everything in line so its quicker to read and know that they are all behaving the same way.

[t-eckert]

Great work!

[curtbushko]

Looks pretty good! I have a few questions/suggestions but nothing in particular that I would block on.