fix: fill defaults for non-required field of type "record" (#336)

* fix: fill defaults for non-required field of type "record"

* Ignore fields which differ across kong versions from tests

* Add version check for test failing due to schema changes across versions

* Pin version to 3.3.0 for test failing due to  schema changes

* Add schema to test itself
As acme plugin's schema has varied a lot over different versions of kong, it is easier to handle if this is added to the test itself

---------

Co-authored-by: Nishant H <nishantho@zeta.tech>
Co-authored-by: Travis Raines <571832+rainest@users.noreply.github.com>

kong/utils.go

@@ -250,7 +250,9 @@ func fillConfigRecord(schema gjson.Result, config Configuration) Configuration {
 			}
 		}
 		ftype := value.Get(fname + ".type")
-		if ftype.String() == "record" {
+		frequired := value.Get(fname + ".required")
+		// Recursively fill defaults only if the field is either required or a subconfig is provided
+		if ftype.String() == "record" && (config[fname] != nil || (frequired.Exists() && frequired.Bool())) {
 			subConfig := config[fname]
 			if subConfig == nil {
 				subConfig = make(map[string]interface{})