Rename CLI option "--trace" to "--explain"
Harmonize option naming between CLI and API endpoint.
Rename --trace option to --explain option.
When you execute a simulation on the CLI :
trefle simulate --context='{"beneficiaire":{"age":40},"formation":{ "codes_financeur":[2],"region":27,"heures":4000}}' --trace
with option --trace you get verbose explanation. The API endpoint use the option explain=1 to have the same verbose explanation.