Add system resource monitoring RESTCONF/NETCONF notifications (CPU, memory, disk, ...)

[mattiaswal]

Description

Example sensors:

• CPU utilization
• Memory usage
• Disk space
• System temperatures

Implementation:
Use the ietf-hardware YANG model (RFC 8348) as the foundation. This standard model already defines the structure for hardware components and sensor data, and is widely supported by network management systems.

Additional Information

For SNMP, there are at least these two MIBs covering CPU and memory usage.

• HOST-RESOURCES-MIB
• UCD-SNMP-MIB

General Information

Anyone can help out by sponsoring development of new features or contributing pull requests.
Please use this issue for discussions related to the feature.

[mattiaswal]

Pushed a branch (restconf-notfications), that send a simple notification. tested with restconf only.