SteamID: make_steam64 should either raise on invalid input, or always return invalid SteamID

[rossengeorgiev]

Spawned from #259

invalid SteamID = SteamID(0, EType.Invalid, EUniverse.Invalid, 0)

For numeric input, invalid values do not raise, and instead create a invalid SteamID instance:

https://github.com/ValvePython/steam/blob/92c5107c7c300d55d37d9e681de8394d78fca841/steam/steamid.py#L296-L298

For string input, invalid values do not raise, and instead create a invalid SteamID instance:

https://github.com/ValvePython/steam/blob/92c5107c7c300d55d37d9e681de8394d78fca841/steam/steamid.py#L310-L311

For out of bounds, we raise some times.

I think all input should be validated, and if its out of bounds, raise. Then the user can create a invalid SteamID instance if needed (which is technically not out of bounds). This will additionally, make catching bad input, and potential changes the SteamID format by Valve. Explicit is better.

If we silently ignore out of bounds conditions, and return invalid SteamID instance, then that can result in unexpected behavior. Suppose SteamID is initialized before queries are made for database. Then suppose, Valve adds a new type, that the code can't handle. All valid SteamIDs will then turn into invalid SteamID and will silently be collapsed under a single SteamID. That is bad