Add curtime logical gate

[Gabriel-V-Maia]

I think the PR's name is pretty self explanatory

The Curtime gate outputs CurTime() if CLK is different than zero, otherwise it just outputs the last saved number.

[thegrb93]

Is there a use case that can't be resolved using a timer gate?

[Gabriel-V-Maia]

Yes, such as timestamping moments, in one of my contraptions I had to use an e2 chip to output CurTime, the timer is more of a stopwatch then something that provides the uptime of a server.

There may have other ways to do such things without a CurTime gate, but I don't see harm on adding one, plus I saw another person looking for it on discord, so maybe it will help them on the future, and help other people looking for one too. (I suppose most people try other alternatives as they know from their experience that there isn't a CurTime gate, instead of asking if there's one or whatsoever)