Simplify WiFi datamodel mapping

docs/guide/manage_wifi_network.md

+# How to Manage WiFi Network using TR181
+
+## Aim
+Currently TR181 (2.19.1) provides multiple ways to manage WiFi network, this guide/document describes do/don't/how for most common operations done by Operator/End-User.
+
+## TR181 WiFi Object
+
+TR181 provides `Device.WiFi` object to manage the Wireless network which includes
+
+- Native nodes:
+
+1. `WiFi.Radio.`
+2. `WiFi.SSID.`
+3. `WiFi.AccessPoint.`
+
+- EasyMesh Node:
+
+1. `WiFi.DataElements.Network.`
+
+Native nodes responsible to manage Wireless on Current CPE, where as EasyMesh Node(DataElements.Network.) meant for whole home wireless management.
+
+### Open Issues
+
+1. Currently there is no standard way to identify if Native nodes are part of EasyMesh Network or its a standalone configuration
+2. Some configuration only applicable with Standalone native node, (like Radius Configuration, WPA3 support etc...)
+3. No standard way to add/list MLD units
+
+### datamodel handling
+
+To address the open issues and to provide a seamless experience for basic wireless management, we extended the TR181 support with the help of vendor extensions
+
+1. A newly added AccessPoint/SSID from TR181, will result into Easymesh FrontHaul AP
+2. Vendor extension in `WiFi.AccessPoint.X_IOWRT_EU_MultiAPMode` to show and configure 'multi_ap' flag in wireless config, this will allow user/operator to de-link/convert an EasyMesh FrontHaul AP to standalone AP, users/operators only allowed to update this value from '2' (fronthaul AP) to '0' (Standalone AP)
+3. Only update of basic parameters like SSID/Encryption Type/Password is allowed for EasyMesh fronthaul APs using WiFi Native nodes, any other update/Set result into error
+4. Setting of `WiFi.SSID.{i}.MLDUnit` only allowed if target SSID instance already commissioned in an AccessPoint
+5. In case of User/Operator set the MLDUnit to '-1', this will result into de-linking the fronthaul-AP from MLD and will result into a SLO interface
+6. In case of User/Operator set the MLDUbit to a value for which mld-unit already exits, then it will apply the SSID/Credentials from 'config mld' section to this new SSID and AccessPoint instance
+7. In case of User/Operator updates any details using Native nodes, datamodel will propagate that details to mapcontroller (in case of multi_ap=2) and it will result into updation of SSID/Key in 'config mld' section as well if Native node is part of a existing MLD Unit
+8. `SetSSID()` operate command will be optimized to check if the configuration applied to network or not, it may take upto 70 seconds to return
+
+## References
+
+1. [TR181 - WiFi Theory of Operation](https://device-data-model.broadband-forum.org/index.pdf#%5B%7B%22num%22%3A74%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22XYZ%22%7D%2C72.857254%2C729.144%2C0%5D)
+2. [TR181 - WiFi datamodel](https://usp-data-models.broadband-forum.org/tr-181-2-19-1-usp.html#D.Device:2.Device.WiFi.)
+