Adding lldp-poe agent to handle LLDP negotiation and multiple fixes and improvements in dentos-poe-agent

[vlaggeor]

• Refactoring existing code
• adding lldp-poe agent to handle LLDP negotiation, on top of the already existing L1 negotiation, for more precise power budgeting
• Sanitise usage of resources
• Add watchdog to detect chipset hung, restart poed and reset chipset in order to recover from this state
• Add gRPC communication between poecli and poed
• Read messages safe from PoE chipset
• Add overrider for hardware status for use during testing
• wait for the poed threads to complete before system exit for poed process to be killed gracefully during update
• Compact System mask registers print
• reduce un-necessary logging in poed and lldp-poe
• Use /etc/onl/platform as source of truth if possible