Add O-Counter for Performers and Sort/Filter Performers by O-Counter (#3588)

* initial commit of sort performer by o-count

* work on o_counter filter

* filter working

* sorting, filtering using combined scene+image count

* linting

* fix performer list view

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Co-authored-by: jpnsfw <none@none.com>

pkg/models/performer.go

@@ -110,6 +110,8 @@ type PerformerFilterType struct {
 	ImageCount *IntCriterionInput `json:"image_count"`
 	// Filter by gallery count
 	GalleryCount *IntCriterionInput `json:"gallery_count"`
+	// Filter by O count
+	OCounter *IntCriterionInput `json:"o_counter"`
 	// Filter by StashID
 	StashID *StringCriterionInput `json:"stash_id"`
 	// Filter by StashID Endpoint