Multiple minor runtime-related improvements

[kostko]

No description provided.

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[peternose]

Could also be done top-down:

// Check for any overrides in the node configuration.
compCfg, ok := config.GlobalConfig.Runtime.GetComponent(comp.ID())
if ok && compCfg.Disabled {
	continue
}

// On non-compute nodes, assume all components are disabled by default.
if !ok && config.GlobalConfig.Mode != config.ModeCompute {
	continue
}

// By default honor the status of the component itself.
if !ok && comp.Disabled {
	continue
}