PLT-6358: Server HTTP client improvements (#6980)

* restrict untrusted, internal http connections by default

* command test fix

* more test fixes

* change setting from toggle to whitelist

* requested ui changes

* add isdefault diagnostic

* fix tests

model/config.go

@@ -158,6 +158,7 @@ type ServiceSettings struct {
 	EnableDeveloper                          *bool
 	EnableSecurityFixAlert                   *bool
 	EnableInsecureOutgoingConnections        *bool
+	AllowedUntrustedInternalConnections      *string
 	EnableMultifactorAuthentication          *bool
 	EnforceMultifactorAuthentication         *bool
 	EnableUserAccessTokens                   *bool
@@ -629,6 +630,10 @@ func (o *Config) SetDefaults() {
 		*o.ServiceSettings.EnableInsecureOutgoingConnections = false
 	}
 
+	if o.ServiceSettings.AllowedUntrustedInternalConnections == nil {
+		o.ServiceSettings.AllowedUntrustedInternalConnections = new(string)
+	}
+
 	if o.ServiceSettings.EnableMultifactorAuthentication == nil {
 		o.ServiceSettings.EnableMultifactorAuthentication = new(bool)
 		*o.ServiceSettings.EnableMultifactorAuthentication = false