Scl-loader

**Full Changelog**: https://github.com/rte-france/SCL_Loader/compare/v1.9.2...v1.9.4

What's Changed
BREAKING CHANGE : DataSets are now managed by list

* https://github.com/rte-france/SCL_Loader/pull/20
* Fix bug DataSet 19 in https://github.com/rte-france/SCL_Loader/pull/21


**Full Changelog**: https://github.com/rte-france/SCL_Loader/compare/v1.9.1...v1.9.2

What's Changed
* Add some functions to IED class

**Full Changelog**: https://github.com/rte-france/SCL_Loader/compare/v1.8.1...v1.9.0

This release contains various improvments:
* fix tests get extrefs
* get_inputs_goose_extrefs to LD …
* Adding test for new getters functions
* Adding get_IP_adr
* Clear self.tIED
* get LD and get LN

* change get_inputs_goose_extrefs to return all extref attributes
* add get_inputs_goose_extrefs to LD
* add get_children_LDs to IED