feat: Grouped surveys and source gen.

Adding the functionality to group surveys and run source gen on each groups. Grouping is only run if it is defined in the config (otherwise it use all available surveys), and it is based on the 'Origin' column of the surveys. All unique 'Origin' will create its own group alongside the ones defined in the config. Groups can be ignored by defining 'GroupsToIgnore' in the config (this has no effect on 'Origin' types).