Assorted fixes

Power armor interface:

The check for a power source checked the maximal bionic power, instead the current power (would allow to activate the item with 0 power), fixed.
It was not possible to deactivate the armor without a charges UPS, the function would skip the deactivation and only print a message "Your %s powers down." - which it actually did not. The out of power case is implemented in `player::process_active_items`. Fixed.


I can't reproduce #9878 (can someone else?):

> I have Power Armor interface Mark2 bionic installed but not activated
> I haven't any UPS in inventory
> But i can activate my heavy power armor and it starts to drain my bionic energy

It works fine here, the game prints the appropriate message and does not activate the item.

Start without UPS, with both power armor interface bionics (both inactive) and some bionic power:
- activating the armor is declined with the correct message
- picked up a (loaded) UPS, now the armor can be activated.
- dropping the UPS deactivates the armor.
- activating both bionics, or activating only one allows the armor to be activated.
- deactivating both bionics while the armor is active makes the armor deactivate itself (one needs to wait a turn because deactivating a bionic does not take move points).

----

Artifact materials: http://smf.cataclysmdda.com/index.php?topic=8217 - same problem as faction description, materials are lost for good, on the upside no material means no rust and no acid damage and no fire damage - the artifacts are indestructible (-:

----

Inventory ui: fix column width - http://smf.cataclysmdda.com/index.php?topic=8196 - previous code did not include the single character column between the main inventory list and the worn item list. Together with the two 40 character wide item lists, it would print lines of 81 (40+1+40) characters, clearly one to many for small screens.

----

Fixes #9931 - toggle mutation key binding, was correct in json, but incorrect in the code.