…3 library, enhanced command handling and error management..

Extended description:
- Migrated to telnetlib3 for improved handling of Telnet commands and options.
- Upgraded TelnetConnection with error handling in send and close methods.
- Refined AsyncioTelnetServer by inheriting from telnetlib3.TelnetServer, featuring streamlined command processing and enhanced logging.
- Removed unnecessary dependencies and imports, simplifying the codebase.
- Retained the core execution flow, adapting it to the new class structures.

Observation for Future Improvement:
- Some NVT commands are still marked as unhandled in debug logs despite having the necessary handling statments. This behaviour may be related to certain user-reported bugs.
- Further comprehensive testing and diagnostics are needed to understand and resolve these issues.

Next Steps:
- A detailed code review focusing on prerequisites and requirements is suggested. This will determine which functions can be effectively delegated to telnetlib3 without negatively impacting other GNS3 modules.
- The goal is to ensure optimal integration of telnetlib3, maximizing efficiency while preserving the integrity and functionality of the broader GNS3 ecosystem.