/kind cleanup

What this PR does / why we need it:

Replaces two custom helpers in operator/internal/controller/common/component/utils with their direct samber/lo equivalents:

• Deletes MapBy (and its tests) in favor of lo.SliceToMap. MapBy was a one-to-one re-implementation; callers in lookups.go and podgang/syncflow.go now use lo.SliceToMap
  directly.
• Replaces the lo.Reduce(..., agg || …, false) fold in isStandalonePCLQ with lo.SomeBy. Same semantics, but SomeBy short-circuits on the first match instead of walking the full
  slice, and the intent ("does any config contain this clique?") is expressed directly.

No behavior change. Pure refactor to lean on the upstream library and shrink the local utils surface.

Which issue(s) this PR fixes:

Fixes #567

Special notes for your reviewer:

• NewSet / NewSetBy were left in place: they return the package's Set[T] = map[T]struct{} typedef with a Has method, and lo has no equivalent set type — swapping them in would
  lose the named type and method.
• groupPCLQsByLabel / groupPCSGsByLabel were also left alone: they filter items missing the label and group, so a one-to-one swap to lo.GroupBy isn't possible (would require
  lo.GroupBy(lo.Filter(…), …), a composite rather than a direct replacement).

Does this PR introduce a API change?

NONE

Additional documentation e.g., enhancement proposals, usage docs, etc.: