Opensvc daemon status and warning based on treshold

[caffeinated92]

This pull request introduces new monitoring and warning mechanisms for OpenSVC orchestrator nodes, focusing on memory and swap thresholds, and improves the reliability and performance of OpenSVC stats collection. It also includes minor fixes and enhancements to the dashboard display and error messaging.

OpenSVC node health monitoring:

• Added the CheckOpenSVCTresholds method to Cluster to monitor nodes for minimum available memory and swap thresholds, setting new warning states (WARN0150, WARN0151) when thresholds are breached.
• Introduced new error messages in config/error.go for memory and swap threshold breaches (WARN0150, WARN0151).

OpenSVC stats handling improvements:

• Updated DaemonNodeStats struct to include MinAvailMem and MinAvailSwap fields, and modified the stats extraction logic to retrieve these values. [1] [2]
• Changed the behavior of GetOpenSVCStats to return an empty slice instead of an error when not using OpenSVC, improving downstream logic.

Concurrency and performance enhancements:

• Made OpenSVC stats reload in ReplicationManager concurrent and protected with a flag to prevent overlapping fetches, improving performance and reliability. [1] [2] [3]

Dashboard calculation fix:

• Corrected the calculation of used memory and swap in the OpenSVC dashboard component to use percentages, ensuring accurate display.