[CLEANUP] Remove code for unused vendors

[danry25]

Remove long dead vendors including Teli, Peerless, Call48 and Data247

Specifically in https://github.com/AccelerateNetworks/NumberSearch/blob/8cd3d575c14b2240cc71b1354a858845f411f509/NumberSearch.Mvc/Models/MvcConfiguration.cs and related files nix:
TeleAPI
CallFlow
ChannelGroup
PeerlessAPIKey
Data247Username
Data247Password
Call48Username
Call48Password

Additionally remove LIDBLookup.GetAsync comments from Integration Tests since this function no longer exists.

[danry25]

@uncheckederror Please review these changes and ping me once you push the new build to production so I can test.

I believe the CallFlow & ChannelGroup variables were values we were setting on the long dead Teli.net platform to route inbound calls to the correct server, and to have them billed against the appropriate group of inbound calling channels.