What you want is not possible. VLC only implements the DLNA media renderer service, the TV unfortunately also does the same. VLC does work with googlecast but not with miracast and for most likely legal/licensing reasons webos does not have support for Chromecast.
The TV searches and it wants to find a server but VLC is not a server.
Also on UPNP and DLNA they are often used together or interchanged because DLNA uses UPNP but only on the local network. Most routers disable UPNP by default for security reasons and Dlna still works on the LAN.
