dev-uxmt: Fix discovered migration flow issues

[jpkrajewski]

Pull Request summary:

Fix:

• VPN INTERFACE: Static IP address with device specific value converted to dynamic IP address
• VPN: Migration Cisco VPN Feature Template with IPSec route fails and lan/vpn parcel is not created
• VPN: KeyError: 'aggregate_only' during Cisco VPN feature template migration
• SECURITY: Constant value convernted to variable value for integrity-type from Cisco Secuirty feature template
• Interfaces: Incorrect value for static IPv4 address after migration to ux2. Use IP address instead of network address
• lan/vpn/interface/ethernet: ValidationError: 3 validation errors for VrrpIPv4 #758

Description of changes:

[Add more in depth analysis of what changed, provide logs, examples of usage]

Checklist:

• Make sure to run pre-commit before committing changes
• Make sure all checks have passed
• PR description is clear and comprehensive
• Mentioned the issue that this PR solves (if applicable)
• Make sure you test the changes