Proto, Tx_rollup: add withdraw operation to layer-1

Context

Part of #2259 (closed)

This MR implements the Layer 1 side of the withdrawal. It allows to send tickets that was pulled off layer 2 by a l2 operation withdraw.

Manually testing the MR

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR