MVHub::CGIAppBase missing POD

[Priya Ravindran]

CGIAppBase has public methods now retr_select_sql and get_config_param.

The old POD should be fixed to include the public methods.

modify below the line with __DATA__ in:

    lib-mvhub/lib/MVHub/CGIAppBase.pm

to correct SYNOPSIS which says there are no public methods
to add a Methods/Subs section which documents these two public methods

See:
   man POD
  # for examples of documented subs:
   perldoc MVHub::Utils
   more lib-mvhub/lib/MVHub/Utils.pm