Implement time:* 4.0.0 commands (#736)

* Abstract SteadyClockCore to follow Nintendo changes in 4.x

This is the ground work for 4.0.0 support

* Implement TickBasedSteadyClockCore

Preparation for the ephemeral clock.

* Refactor SystemClockCore to follow 4.0.0 changes

* Implement EphemeralNetworkSystemClock

* Implement GetSnapshotClock & GetSnapshotClockFromSystemClockContext

* Implement CalculateStandardUserSystemClockDifferenceByUser & CalculateSpanBetween

* Remove an outdated comment & unused import

* Fix a nit and GetClockSnapshot

* Address comment

Ryujinx.HLE/HOS/Services/Time/ITimeZoneService.cs

@@ -56,7 +56,6 @@ namespace Ryujinx.HLE.HOS.Services.Time
         // LoadLocationNameList(u32 index) -> (u32 outCount, buffer<nn::time::LocationName, 6>)
         public ResultCode LoadLocationNameList(ServiceCtx context)
         {
-            // TODO: fix logic to use index
             uint index          = context.RequestData.ReadUInt32();
             long bufferPosition = context.Request.ReceiveBuff[0].Position;
             long bufferSize     = context.Request.ReceiveBuff[0].Size;