Packages: Add logic for evm-node as a sequencer

What

This MR adds configuration logic so that the evm-node can be run in sequencer more as well as proxy mode.

Why

The evm node now supports sequencer mode and is being used on the Ghostnet Etherlink MVP. Eventually a partner may need to run a sequencer

How

Variable changes made to the script with logic to support them.

Manually testing the MR

make dpkg

Test the package in proxy and sequencer mode (both have been done this morning on the Etherlink MVP)

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