chore: eventually try to also increase unit test cov on certain modules

[viniarck]

The current unit test total cov is at 90%, which is great and covers all the critical paths and many exceptional paths too, but certain exceptional paths expecially on main.py could be better covered, eventually it'll be done, mapping here to be on our radar:

---------- coverage: platform linux, python 3.11.8-final-0 -----------
Name                                        Stmts   Miss  Cover
---------------------------------------------------------------
exceptions.py                                  31      4    87%
kytos_api_helper.py                            76     15    80%
main.py                                       212     87    59%
managers/int.py                               279     52    81%
proxy_port.py                                  24      3    88%

---------------------------------------------------------------
TOTAL                                        1654    164    90%


Related to https://github.com/kytos-ng/telemetry_int/pull/82