Add support for EXOS

[rafabr]

This current implementation was tested and is working with the following images (EXOS images are easily found in the official Extreme Networks github page):
EXOS-VM_v22.4.1.4-disk1.qcow2
EXOS-VM_v32.6.3.126.qcow2
This implementation also partially worked with older versions of EXOS (tested with EXOS-VM_v16.1.1.4-disk1.qcow2 and EXOS-VM_v21.1.1.4-disk1.qcow2). The bootstrap and initial configuration were successfully applied, and SSH access was possible. However, testing showed high latency and packet loss during ping tests between hosts.

If anyone with more experience in emulating these systems could provide insights or suggestions to help resolve the connectivity issues, it would be greatly appreciated.

Notes:

• The startup configuration functionality is implemented based on Method 1 from the official documentation
• For accuracy, STARTUP-CONFIG file should ideally be in the .xsf format. However, the current implementation temporarily supports only the .cfg format to facilitate testing using existing kinds
• The startup configuration will not override the management VLAN IP settings. If an .xsf file contains a command that attempts to configure the management VLAN's ipaddress, the system will log an error and skip the command. I'm assuming that the IP configuration from the bootstrap config should take precedence over the provided configuration.
• Following the official documentation, using the upload config command to save the system configuration will generate an .xsf file that contains lines which may cause errors during import with the load script command. However, the system will continue applying the configuration while ignoring these errors. Attempts to clear all configurations before importing did not resolve the issue, and I'm assuming that those familiar with EXOS are aware of this limitation.

Discord

Discussion thread in discord

[rafabr]

No progress was made with versions older than 22; however, I believe it could still be merged, as it works properly with more recent versions. I will be moving it from draft to ready for review

[hellt]

thanks @rafabr let's roll it