Currently packages are validated by the Engine before Speedy compilation, but not when uploaded to the Ledger.

The package should be validated before to be stored on the Ledger as part of the package upload process.
This has two main advantages:

• this avoids to store bogus data on the ledger that cannot be latter used.
• this allowed to skip validation in the Engine, then speeding up submission when packages are not available in the Engine.

Proposal

1 - The participant Node validate the packages before sending them to the ledger.
This prevents the ledger to validated buggy archive, since this can be very costly in a distributed system.
2 - The ledger revalidate the package before committing, reject if invalid
3 - Drop the validation in the Engine.