REFACTOR: Rpyc service logic and clean up

[SMoraisAnsys]

Description

This PR focuses on refactoring the remote session management and RPyC service logic. The main goal is to modernize, modularize, and clarify the architecture for launching and managing remote AEDT sessions, making the codebase more robust, maintainable, and user-friendly. There is still a lot of possible improvements but the rpyc logic is currently tightly coupled to the code and reworking it further would require feedback from users to better understand what we could do and shouldn't.
Also, the ability to work with secure/insecure & listening on all interfaces have been added and should be backward compatibly with AEDT versions not using the new SPs or 2026.1. Note that the current changes draw a strict line that rpyc should only be used when working with gRPC using mTLS or insecure connections. Any use of WNUA / UDS is not handled.

Issue linked

Related to #7288, #7365 and #7321.

Checklist

• I have tested my changes locally.
• I have added necessary documentation or updated existing documentation.
• I have followed the coding style guidelines of this project.
• I have added appropriate tests (unit, integration, system).
• I have reviewed my changes before submitting this pull request.
• I have linked the issue or issues that are solved by the PR if any.
• I have agreed with the Contributor License Agreement (CLA).