Add support for DW2-Wi-Fi-L

[denes-sebestyen]

This device is a door opening detector that works through the eWeLink site.
When I tried scanning with the Sonoff Binding, it didn't show up.
In the log i found this:

2024-03-15 11:26:54.692 [INFO ] [nal.discovery.SonoffDiscoveryService] - Discovered device 1001f84fda
2024-03-15 11:26:54.695 [ERROR] [nal.discovery.SonoffDiscoveryService] - Unable to add 1001f84fda as its not supported, please forward the cache file to the developer

I found a file named /var/lib/openhab/sonoff/1001f84fda.txt

Not entirely sure which part is needed, but there are definitely kinda personal informations in there, so I'd rather not include the whole file if not necessary

However I'm happy to help in the development for the support