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/channels/smtp/config.go

@@ -1,7 +1,6 @@
 package smtp
 
 type Config struct {
-	Description    string
 	SMTP           SMTP
 	Tls            bool
 	From           string
@@ -18,3 +17,7 @@ type SMTP struct {
 func (smtp *SMTP) HasAuth() bool {
 	return smtp.User != "" && smtp.Password != ""
 }
+
+type ConfigHTTP struct {
+	Endpoint string
+}