Use opalr built-in functions for upload

[ymarcon]

Less hacky code, with backward compatibility:

• to apply a data dictionary to a tibble (i.e. before saving it): https://www.obiba.org/opalr/reference/dictionary.apply.html
• to save a tibble as a opal table: https://www.obiba.org/opalr/reference/opal.table_save.html
• to update a table data dictionary (i.e. after a tibbla has been saved): https://www.obiba.org/opalr/reference/opal.table_dictionary_update.html

See also: https://opaldoc.obiba.org/en/latest/cookbook/import-data/r.html