Add support to NIC / ethX name customization in agent - consistent interface device naming

**Description**
After "recent" changes in linux kernel (more or less since udev is mainstream), interface order of ethernet NICs is not granted.

there was some quickfixes for this in early versions of RHEL5 and Debian (mostly based on MAC), but recently those fixes are been deprecated and now almost all people is using consistent interface device naming aka biosdevname (from dell)

Thats why is neccesary add additional configuration parameter in WALinuxAgent, for example nicname, nicprefix or something like that. (so you can choose nicprefix="nic" as prefix if using nic0, nic1 as interface name or can define nicprefix="en" if using en0, en1 and so on...)

Because of that, network Interfaces can swap interface number randomly between reboots.

for further information, you can refer to this document:
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/configuring_and_managing_networking/consistent-network-interface-device-naming_configuring-and-managing-networking#disabling-consistent-interface-device-naming-during-the-installation_consistent-network-interface-device-naming

And detailed explanation, here:
https://lwn.net/Articles/356900/

**Distro and WALinuxAgent**
- Distro and Version: All Linux distros with kernel <2.6 + udev (thats include, RHEL 6/7/8, Suse and Debian 7/8/9/10
- WALinuxAgent version 2.2.46

Begin by reviewing WALinuxAgent's existing network-interface handling and the Linux consistent naming references linked in the issue. Define the supported configuration parameter and affected distributions before implementation; done means interface names follow the configured prefix without regressions.

Written by the indexing model from the issue text.