feat: add http as smtp provider (#8545)

# Which Problems Are Solved

Send Email messages as a HTTP call to a relay, for own logic on handling
different Email providers

# How the Problems Are Solved

Create endpoints under Email provider to manage SMTP and HTTP in the
notification handlers.

# Additional Changes

Clean up old logic in command and query side to handle the general Email
providers with deactivate, activate and remove.

# Additional Context

Partially closes #8270

---------

Co-authored-by: Livio Spring <livio.a@gmail.com>

internal/notification/handlers/config_email.go

@@ -0,0 +1,56 @@
+package handlers
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/zitadel/zitadel/internal/api/authz"
+	"github.com/zitadel/zitadel/internal/crypto"
+	"github.com/zitadel/zitadel/internal/notification/channels/email"
+	"github.com/zitadel/zitadel/internal/notification/channels/smtp"
+	"github.com/zitadel/zitadel/internal/notification/channels/webhook"
+	"github.com/zitadel/zitadel/internal/zerrors"
+)
+
+// GetSMTPConfig reads the iam SMTP provider config
+func (n *NotificationQueries) GetActiveEmailConfig(ctx context.Context) (*email.Config, error) {
+	config, err := n.SMTPConfigActive(ctx, authz.GetInstance(ctx).InstanceID())
+	if err != nil {
+		return nil, err
+	}
+	provider := &email.Provider{
+		ID:          config.ID,
+		Description: config.Description,
+	}
+	if config.SMTPConfig != nil {
+		password, err := crypto.DecryptString(config.SMTPConfig.Password, n.SMTPPasswordCrypto)
+		if err != nil {
+			return nil, err
+		}
+		return &email.Config{
+			ProviderConfig: provider,
+			SMTPConfig: &smtp.Config{
+				From:           config.SMTPConfig.SenderAddress,
+				FromName:       config.SMTPConfig.SenderName,
+				ReplyToAddress: config.SMTPConfig.ReplyToAddress,
+				Tls:            config.SMTPConfig.TLS,
+				SMTP: smtp.SMTP{
+					Host:     config.SMTPConfig.Host,
+					User:     config.SMTPConfig.User,
+					Password: password,
+				},
+			},
+		}, nil
+	}
+	if config.HTTPConfig != nil {
+		return &email.Config{
+			ProviderConfig: provider,
+			WebhookConfig: &webhook.Config{
+				CallURL: config.HTTPConfig.Endpoint,
+				Method:  http.MethodPost,
+				Headers: nil,
+			},
+		}, nil
+	}
+	return nil, zerrors.ThrowNotFound(err, "QUERY-KPQleOckOV", "Errors.SMTPConfig.NotFound")
+}