[MM-57194] Allow plugins to mark setting fields as secret (#27986)

Co-authored-by: Claudio Costa <cstcld91@gmail.com>

server/channels/app/plugin_api_tests/manual.test_load_configuration_plugin/main.go

@@ -34,6 +34,7 @@ func (p *MyPlugin) OnConfigurationChange() error {
 }
 
 func (p *MyPlugin) MessageWillBePosted(_ *plugin.Context, _ *model.Post) (*model.Post, string) {
+	// Test API.LoadPluginConfiguration
 	if p.configuration.MyStringSetting != "str" {
 		return nil, "MyStringSetting has invalid value"
 	}
@@ -43,6 +44,22 @@ func (p *MyPlugin) MessageWillBePosted(_ *plugin.Context, _ *model.Post) (*model
 	if !p.configuration.MyBoolSetting {
 		return nil, "MyBoolSetting has invalid value"
 	}
+
+	// Test API.GetPluginConfig
+	pc := p.API.GetPluginConfig()
+	if pc == nil {
+		return nil, "GetPluginConfig returned nil"
+	}
+	if pc["mystringsetting"] != "str" {
+		return nil, fmt.Sprintf("MyStringSetting has invalid value: %v", pc["mystringsetting"])
+	}
+	if pc["MyIntSetting"] != float64(32) {
+		return nil, fmt.Sprintf("MyIntSetting has invalid value: %v", pc["MyIntSetting"])
+	}
+	if pc["myBoolsetting"] != true {
+		return nil, fmt.Sprintf("MyBoolSetting has invalid value: %v", pc["myBoolsetting"])
+	}
+
 	return nil, "OK"
 }