IC2: Add converter for reactor components to get stored heat.

[Engineer12798]

With coolant cells and other heat storing items, there is no uniform way in game to extract the heat stored in these items. To do so, would require parsing the NBT of the item stack, which is difficult enough as is, but would also require reading different NBT tags depending on the mod the item came from. To resolve this problem, this PR adds in a converter which will get the stored heat of any item implementing IReactorComponent.

The way the PR works may be jank and not work with some components. There may exist cases where the stored heat and max heat of a component are dependent on the reactor context, which this converter does not provide when trying to get the stored heat.

[OneEyeMaker]

Despite this implementation will work in certain circumstances, one doesn't solve mentioned issue properly. (Even more, one can cause an exception).

Instead I suggest to extend DriverReactor and DriverReactorChamber classes and add necessary methods there.

And only with beforementioned changes present I can suggest to add your implementation for handling components outside reactor. Make sure to mark it explicit and unsafe so players understand what they do. Currently, from player's perspective, these properties you added look like regular (safe) ones.

[OneEyeMaker]

Good job! Now this feature is almost complete.
Just find a way to tell players that original approach is not 100% reliable.