Adapt documentation of all functions

[OLED1]

Many functions are not completely documented but that's crucial.
The following template must be used:
Classes:

/**
   * The Alerting_Api class manages the setup of available server like Gotify, alerting rules and sending alerting using available platform (E-Mail, Gotify, etc.).
   * This class is mainly used by the web(/app) client.
   * @version 0.2
   * @author OLED1 - Oliver Edtmair
   * @since 0.2
   * @copyright Copyright (c) 2022, Oliver Edtmair (OLED1), Luca Austelat (lucaust)
   */

Functions:

    /**
     * <Descripotion e.g. Returns all available alerting services and there enabled status.>
     * Function made for: <Web GUI/App|Backend|Node Client>
     * @ <params... etc.>
     * @throws Exception $e                   Throws an exception on db errors.
     * @param  array $data                    Default: [] (empty) - Returns all availabe services. Can include comma (,) seperated service id's to only return these.
     * @return object                         Returns a promise object: {"status": [0|>0], "message": [Status message], "data": {[Saved DB Values]}}
     */