dpdk: add warning in configuration phase and minor DPDK refactoring v2

[lukashino]

Redmine ticket: https://redmine.openinfosecfoundation.org/issues/6739

v2 changes:

• change the format error message from - (err %s) to : %s

Describe changes:

• SCEnters added
• refactor code to smaller functions
• rewrite log message to be more consistent
• add a user warning on the change of RX/TX descriptors - on changes caused by the NIC adjustment