OSME sourceGeneration params: basic template and types

[FloHin]

Configs are split in several parts:

• mandatory options for sheet constraint
• optional, useful, defined general parameters for algorithms
• optional unspecified parameters for specific plugins

Todo:

• Define data types and structures
• Validate parameters with basic constraints
• Write some tests

[FloHin]

Last Todos:

• [] Add MusicXML source metadata for exercise metadata