Draft: wip signer: update naming

What

WIP

TODO:

• ensure transition from endorsement watermark file to attestation watermark file
• ensure transition from .tezos-signer directory to .octez-signer directory
• check both TEZOS_ and OCTEZ_ env variable

Why

How

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

Summary by CodeRabbit

• Refactor

  • Updated error messaging to use more consistent and clear terminology during attestation operations.

• New Features

  • Enhanced network configuration by supporting an additional environment variable for setting the TCP host.
  • Updated the signer's default data directory to reflect a more consistent naming convention.

These improvements aim to refine error clarity and offer greater flexibility in configuration, contributing to a more intuitive user experience.