Better error message for unqualified family triggers.

Old:
```OPS & VAR_ConfigureLS => VAR_AnalysePF => UM_nzlam
"ERROR, upstream family triggers must be qualified with ':type': OPS"```

New:
```OPS & VAR_ConfigureLS => VAR_AnalysePF => UM_nzlam
'ERROR, family triggers must be qualified, e.g. OPS:succeed-all'