Fixed Fdb.Errors.ValueCannotBeNull and ValueIsTooBig incorrectly throwing instead of returning the exception
Removed a bunch of dead code
Split FdbEndPoint into its own file
Added JetBrains code annotation attributes

- [NotNull] or [CanBeNull] where applicable
- [Pure] for methods on structs (Slice, ...) that don't change the state
- and some more
FdbOperationContext: check early if the cancellation token has expired
Renamed UnmanagedLibrary.LoadLibrary() to Load() + fixed namespace for FdbNativeCluster + misc
Misc fixes