Add support for more generic notification

This is a start to have different kinds of notifications. It is
possible to be notified via e-mail, matrix or gotify. It also extends
the current "periodic query" for due items by allowing notification
over different channels. A "generic periodic query" variant is added
as well.

modules/webapp/src/main/elm/Messages/Comp/NotificationHookManage.elm

@@ -0,0 +1,106 @@
+{-
+   Copyright 2020 Eike K. & Contributors
+
+   SPDX-License-Identifier: AGPL-3.0-or-later
+-}
+
+
+module Messages.Comp.NotificationHookManage exposing
+    ( Texts
+    , de
+    , gb
+    )
+
+import Html exposing (Html, text)
+import Http
+import Messages.Basics
+import Messages.Comp.HttpError
+import Messages.Comp.NotificationHookForm
+import Messages.Comp.NotificationHookTable
+import Messages.Data.ChannelType
+
+
+type alias Texts =
+    { basics : Messages.Basics.Texts
+    , notificationForm : Messages.Comp.NotificationHookForm.Texts
+    , notificationTable : Messages.Comp.NotificationHookTable.Texts
+    , httpError : Http.Error -> String
+    , channelType : Messages.Data.ChannelType.Texts
+    , newHook : String
+    , matrix : String
+    , gotify : String
+    , email : String
+    , httpRequest : String
+    , hookCreated : String
+    , hookUpdated : String
+    , hookStarted : String
+    , hookDeleted : String
+    , deleteThisHook : String
+    , reallyDeleteHook : String
+    , formInvalid : String
+    , invalidJsonFilter : String -> String
+    , integrate : String
+    , intoDocspell : String
+    , postRequestInfo : String
+    , updateWebhook : String
+    , addWebhook : String
+    , notifyEmailInfo : String
+    }
+
+
+gb : Texts
+gb =
+    { basics = Messages.Basics.gb
+    , notificationForm = Messages.Comp.NotificationHookForm.gb
+    , notificationTable = Messages.Comp.NotificationHookTable.gb
+    , httpError = Messages.Comp.HttpError.gb
+    , channelType = Messages.Data.ChannelType.gb
+    , newHook = "New Webhook"
+    , matrix = "Matrix"
+    , gotify = "Gotify"
+    , email = "E-Mail"
+    , httpRequest = "HTTP Request"
+    , hookCreated = "Webhook created"
+    , hookUpdated = "Webhook updated"
+    , hookStarted = "Webhook executed"
+    , hookDeleted = "Webhook deleted"
+    , deleteThisHook = "Delete this webhook"
+    , reallyDeleteHook = "Really delete this webhook?"
+    , formInvalid = "Please fill in all required fields"
+    , invalidJsonFilter = \m -> "Event filter invalid: " ++ m
+    , integrate = "Integrate"
+    , intoDocspell = "into Docspell"
+    , postRequestInfo = "Docspell will send POST requests with JSON payload."
+    , updateWebhook = "Update webhook"
+    , addWebhook = "Add new webhook"
+    , notifyEmailInfo = "Get notified via e-mail."
+    }
+
+
+de : Texts
+de =
+    { basics = Messages.Basics.de
+    , notificationForm = Messages.Comp.NotificationHookForm.de
+    , notificationTable = Messages.Comp.NotificationHookTable.de
+    , httpError = Messages.Comp.HttpError.de
+    , channelType = Messages.Data.ChannelType.de
+    , newHook = "Neuer Webhook"
+    , matrix = "Matrix"
+    , gotify = "Gotify"
+    , email = "E-Mail"
+    , httpRequest = "HTTP Request"
+    , hookCreated = "Webhook erstellt"
+    , hookUpdated = "Webhook aktualisiert"
+    , hookStarted = "Webhook ausgeführt"
+    , hookDeleted = "Webhook gelöscht"
+    , deleteThisHook = "Diesen Webhook löschen"
+    , reallyDeleteHook = "Den webhook wirklich löschen?"
+    , formInvalid = "Bitte alle erforderlichen Felder ausfüllen"
+    , invalidJsonFilter = \m -> "Ereignisfilter ist falsch: " ++ m
+    , integrate = "Integriere"
+    , intoDocspell = "in Docspell"
+    , postRequestInfo = "Docspell wird JSON POST requests senden."
+    , updateWebhook = "Webhook aktualisieren"
+    , addWebhook = "Neuen Webhook hinzufügen"
+    , notifyEmailInfo = "Werde per E-Mail benachrichtigt."
+    }