Implement database handling

[GAGNAIRE-Romain]

Description

• Currently scenario storage is achieved through the use of a local file (formatted in JSON).
• It could be a good idea to implement some kind of storage in a database, so that it is easier to merge multiple data sources (and keep the scenario list up to date).

Goals

• Implement database handler
• Add existing scenario in database
• Handle merging for external sources (whetever being a file or SQL scripts)

Possible tool - DBFlow

• One tool might be very usefull to use DBFlow
• It offers an easy way to manipulate database objects (since it's an ORM)