Performer disambiguation and aliases (#3113)

* Refactor performer relationships
* Remove checksum from performer
* Add disambiguation, overhaul aliases
* Add disambiguation filter criterion
* Improve name matching during import
* Add disambiguation filtering in UI
* Include aliases in performer select

pkg/sliceutil/stringslice/string_collections.go

@@ -1,6 +1,9 @@
 package stringslice
 
-import "strconv"
+import (
+	"strconv"
+	"strings"
+)
 
 // https://gobyexample.com/collection-functions
 
@@ -56,6 +59,19 @@ func StrAppendUniques(vs []string, toAdd []string) []string {
 	return vs
 }
 
+// StrExclude removes all instances of any value in toExclude from the vs string
+// slice. It returns the new or unchanged string slice.
+func StrExclude(vs []string, toExclude []string) []string {
+	var ret []string
+	for _, v := range vs {
+		if !StrInclude(toExclude, v) {
+			ret = append(ret, v)
+		}
+	}
+
+	return ret
+}
+
 // StrUnique returns the vs string slice with non-unique values removed.
 func StrUnique(vs []string) []string {
 	distinctValues := make(map[string]struct{})
@@ -94,3 +110,13 @@ func StringSliceToIntSlice(ss []string) ([]int, error) {
 
 	return ret, nil
 }
+
+// FromString converts a string to a slice of strings, splitting on the sep character.
+// Unlike strings.Split, this function will also trim whitespace from the resulting strings.
+func FromString(s string, sep string) []string {
+	v := strings.Split(s, ",")
+	for i, vv := range v {
+		v[i] = strings.TrimSpace(vv)
+	}
+	return v
+}