Cv backend integration

local start of the server (with fish shell; it may be different on bash):

env SMS_BACKEND_URL="http://rz-vm64.gfz-potsdam.de:5000" CV_BACKEND_URL="http://rz-vm64.gfz-potsdam.de:5001" npm run dev

(But the difference should just be that we don't need the env word on bash).

The CV is also used for some of the combobox fields, according to the current version (2020-07-02) of https://nextcloud.gfz-potsdam.de/apps/files/?dir=/Sensorverwaltung&fileid=1528243#pdfviewer