cubicweb-vcwiki #3734064 Online wiki page creation creates a file with no extension [validation pending]

Its name must rather be completed with the vcwiki's content_file_extension

priorityimportant
typebug
done in0.2.0
load0.100
load left0.000
closed by#c0196f2a4d89 Fix edit controller creates files without extension when creating a wiki page.
patchFix edit controller creates files without extension when creating a wiki page. [applied]