Add missing translation markers for option labels and choice lists

This adds missing N_() translation markers around all of the option text labels and choice labels that I found missing them whilst doing an thorough review of plugin descriptor text labels.

(Unless I've missed a patch in my big cumulative dev branch, or missed one during rebases, apart from one done in a separate MR, this should be all of them - 19 options in 7 plugins + core, 16 sets of choice labels in 9 plugins + core).