[Tavern] Add EnvBool and Update Default Config

[KCarretto]

What type of PR is this?

/kind cleanup

What this PR does / why we need it:

• Adds EnvBool to represent boolean values
• Updates how we log unset environment variables to a uniform style warning that configuration is missing
• Makes the default logger use text output (via ENABLE_JSON_LOGGING)
  • Updated terraform to enable this by default
• Defaults to excluding the tavern instance id from logs (via ENABLE_INSTANCE_ID_LOGGING)
  • Updated terraform to enable this by default
• Allows graphql raw query logging (via ENABLE_GRAPHQL_RAW_QUERY_LOGGING)
  • Updated terraform to enable this by default
• Adds EnvBool testing

[Cictrone]

clean up and then your gucci