(PIE-1329) Secure sensitive data

[coreymbe]

Summary

This PR utilizes the custom function splunk_hec::secure to move credential data to a separate file under a new splunk_hec subdir.

Detailed Description

• Added manifests/v2_cleanup.pp
• Added files/hec_secrets.yaml.epp
• Renamed templates/splunk_hec.yaml.epp -> templates/settings.yaml.epp
• Updated lib/puppet/functions/splunk_hec/secure.rb
  • Function now accepts and returns a hash instead of string
• Updated manifests/init.pp
  • Create /etc/puppetlabs/puppet/splunk_hec directory for config files.
  • Move credentials to hec_secrets.yaml
  • Remove splunk_hec.yaml via ::v2_cleanup subclass
  • Remove splunk_hec_routes.yaml via ::v2_cleanup subclass
• Updated lib/puppet/util/splunk_hec.rb
  • Utilize credentials from hec_secrets.yaml
• Updated templates/util_splunk_hec.erb
  • Utilize credentials from hec_secrets.yaml

Checklist

[X] Ensure README is updated
[X] Any changes to existing documentation
[X] Anything new added
[X] Link to external Puppet documentation
[X] PR title is "(Ticket|Maint) Short Description"
[X] Commit title matches PR title

[coreymbe]

This is currently failing tests on Puppet 8 due to PUP-11846.

The test against puppet8-nightly should pass once Puppet 8.2 is released.