Adds configuration for separate reply-to email header. (#10144)

* Adds configuration for separate reply-to email header.

* Changes config setting name.

* Using a separate variable and value in test.

* Updates for config pointer changes in another PR.

* Adds new key to test config. Adds default value.

app/diagnostics.go

@@ -389,6 +389,7 @@ func (a *App) trackConfig() {
 		"enable_preview_mode_banner":           *cfg.EmailSettings.EnablePreviewModeBanner,
 		"isdefault_feedback_name":              isDefault(cfg.EmailSettings.FeedbackName, ""),
 		"isdefault_feedback_email":             isDefault(cfg.EmailSettings.FeedbackEmail, ""),
+		"isdefault_reply_to_address":           isDefault(cfg.EmailSettings.ReplyToAddress, ""),
 		"isdefault_feedback_organization":      isDefault(*cfg.EmailSettings.FeedbackOrganization, model.EMAIL_SETTINGS_DEFAULT_FEEDBACK_ORGANIZATION),
 		"skip_server_certificate_verification": *cfg.EmailSettings.SkipServerCertificateVerification,
 		"isdefault_login_button_color":         isDefault(*cfg.EmailSettings.LoginButtonColor, ""),