[LTC] Inherits LazyGraphExecutor::DeviceContextArena (#4307)
Summary:
This patch inherits LazyGraphExecutor::DeviceContextArena and overrides the follow methods:
1. GetLiveTensors to return XLATensorPtrs.
2. GetRngSeed to use our own + and * for torch::lazy::Value.
3. IrValueFromScalar to use TensorToXlaData.
In addition, it has an extra method: GetBaseSeedData that is used by dynamo.
This patch needs pytorch/pytorch#90531 to function.
Test Plan:
CI.
