Edit WebSubmit Function

  Set the global variable 'rn' to the report number of the record
  identified by 'sysno' (recid) global variable.

  Useful at MBI step when the user specifies the record to modify
  using the recid instead of the report number.  Since most
  WebSubmit functions relies on the global 'rn' variable, it is
  necessary in these cases to include this function.

  This function MUST be preceded by 'Get_Recid' function.

  To identify the record to update via 'recid' instead of report
  number, one MUST on the MBI form request the recid/sysno using a
  form element named 'SN'.

  Parameters:

       edsrn - file where to write the report number if found

    rep_tags - comma-separater list of tags where the report number
               can be found. Default is '037__a', '088__a', '021__a'
               if no value is specified.

record_search_pattern - this enforces restrictions on which type of
               documents can be modified via a certain submission
               interface. If the record_search_pattern is not
               defined, no restriction will be enforced.  The
               record_search_pattern can be anything that can be
               used by search_pattern to search for. Also, one can
               use variables stored locally, like
               <comboDEMOJRN> to denote the category or
               subcategory.
               Ex:
                  reportnumber:DEMO-<comboDEMOJRN>-*
                  collection:ATLANTISTIMESNEWS
                  reportnumber:DEMO-<comboDEMOJRN>-* | collection:ATLANTISTIMESNEWS

               As a note, you can test your pattern, using the
               search engine and see if it retrieves the expected
               results.

               WARNING: this check is not applied if the report
               number has already been written to 'edsrn' file.

  Exceptions raised:
      + InvenioWebSubmitFunctionStop
            - if trying to access unauthorized path to read/write report number;
            - if accessing a recid that does not exist or is deleted;
            - if recid should not be handled by the current submission;