Merge branch 'f-hide-properties' into 'dev'

build.properties.d/00_default.properties

conf/core/json/ext_prop_display.json

src/core/css/webcaosdb.css

src/core/js/edit_mode.js

src/core/js/ext_prop_display.js

src/core/webcaosdb.xsl

src/core/xsl/entity.xsl

src/doc/extension/display_of_properties.rst

test/core/js/modules/ext_prop_display.js.js