[uk] Update core_encounter.json for UA translation

Changed card names and keywords mostly, didn't touch flavor text. 

Updated translation that came with the release of the "Revised core set" and will be carried into all future expansion releases including upcoming Edge of the Earth campaign.

Full details (including eng-new-old changelog breakdown) from the publisher can be found here:
https://docs.google.com/spreadsheets/d/11HLftr5kuqZkqm64KE-XZLtzXhjRnTyUYhY_J1rACdw/edit?usp=sharing