feat/store-ranges-smaller-tree-and-deduplication

[nohehf]

• The IP tree is now binary
• Reduced IP tree size by ~3x
• Tree now properly deduplicates networks, by only keeping the largest ones (duplicates, or subnetworks will be dropped).
• Ranges are now stored in ./ranges, one .txt file per provider. They're extracted after building the tree, meaning that they benefit from the deduplication.
• go stringer was replaced by go-enum for enum generation, to allow for more customization, and checking at build time that the enum / sources are correctly mapped