fix(magistrate): delegate check only needed on entity register

[air1one]

Summary

Entity delegate transactions have a specific check against the sender wallet which needs to be a delegate and username must match entity name.

But this check is only needed for register : as an update or resign needs first a register tx where the delegate check was already done.

This also fixes an issue with current implementation where update or resign entity delegate tx would not be accepted because of the name check which was incorrectly implemented.

Checklist

• Documentation (if necessary)
• Tests (if necessary)
• Ready to be merged