Fix/proxy close

[pappz]

Describe your changes

Revert the context cancellation logic from the wg proxy and improve the error handling in case of resource freeing action.

• In eBPF proxy implementation we can not close individual turn connections. It frees up in an implicit way if the ice agent closes the conn.
• We should not mix in the resource freeing logic the context cancellation with the exported "close" functions. In the eBPF proxy was CloseConn(), Free(), and cancel by parent context.

Issue ticket number and link

Checklist

• [x] Is it a bug fix
• [ ] Is a typo/documentation fix
• [ ] Is a feature enhancement
• [ ] It is a refactor
• [ ] Created tests that fail without the change (if possible)
• [ ] Extended the README / documentation, if necessary