mz_entity - documentation missing for some options

Documentation seems to be missing for some mz_entity options, leading to incomprehensible behaviour.

mz_entity -U $MYREPO --grab --uuid 56ED7836FCE8A2BBD0CD3A54B12E2273DB35BBA180110F4DADA4D7FA65B14AB8

    ### ====================================================================
    ### MOSAIC (v1.0) - 2023-11-08T14:03:18
    ### 
    ### In rack : 
    Traceback (most recent call last):
      File "/softs/mosaic/1.0/ref/bin/mz_entity", line 696, in <module>
        parse_and_proceed()
      File "/softs/mosaic/1.0/ref/bin/mz_entity", line 287, in parse_and_proceed
        parse_and_proceed_args(args, db, mzlog)
      File "/softs/mosaic/1.0/ref/bin/mz_entity", line 643, in parse_and_proceed_args
        mzlog.info(f'{resp[0]}')
    TypeError: 'NoneType' object is not subscriptable

Comment: Unclear error

mz_entity -R --owner D053293 --uuid 56ED7836FCE8A2BBD0CD3A54B12E2273DB35BBA180110F4DADA4D7FA65B14AB8 $MYREPO

    ### ====================================================================
    ### MOSAIC (v1.0) - 2023-11-08T14:08:41
    ### 
    ### Entity                           Platform                         Team                             Rack                            

    ### 
    ### ====================================================================

Comment: No return on a file whose owner is the one indicated with the owner option

mz_entity -R --owner D053293 $MYREPO

    ### ====================================================================
    ### MOSAIC (v1.0) - 2023-11-08T14:08:54
    ### 
    ### Entity                           Platform                         Team                             Rack                            

    ### 
    ### ====================================================================

Comment: Maybe there should be an indication on what the user did wrong