[MERGED PR] Merges mechanics with engineer

[Ikea]

The RKIT is a definite overlap between the two jobs, so moving it to something like a shared construction room wouldn't be a horrible idea. The ABC-U could also be included here along with other building supplies.

See https://github.com/goonstation/goonstation/pull/3838 for reasons why that wouldnt be great, itd run into all the challenges that this pr may bring about, with none of the upside. 

Personally, even if mechcomp and packets had enough content to be enough for a full fledged job and didnt run into the issue it runs into now where most of the stuff you can do with it is miscreant tier (which wouldnt be nearly as much of an issue if a job wasnt forced to focus on it if they wanted to actually do something), I still wouldn't support a job just for that. I'd much prefer if interacting with packets was something that was spread out (even if indirectly for most jobs), instead of one sole job for it.

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Giving them more options for how to power the station would be nice. Also electrical faults do not happen nearly enough, giving them a lack of purpose beyond initially getting the power running.

This is something I agree with as well. There needs to be more events or things that can go wrong with the electrical system / engine to actually warrant a repair role as a primary occupation. As it stands, the majority of the time, Engineers don't really have to repair anything unless there's an arcfiend around or a meteor hits the station, both which is highly variable by not happening at all.

I agree with the rough sentiment of this, even though Id prefer to give them additional "challenges" when they decide to put in more work for the electrical grid, and having this work be rewarding to the crew and the engineer, instead of more challenges for simply existing (as the latter tends to lead to toxicity when engineers are unable to help, when the former gets people gracious when an engineer helps them out). However this pr isn't really about that aspect of engineering. The engineer job will still have issues after this and this will by no means be a silver bullet. There will still be more work that can (and should) be put into making sure the engineering side of engineering is solid, this pr is more focused on the construction side. This wont fix all the issues with constructing things as engineer of course, however it should hopefully help a ton.