Minor refactor for handling of LoggableDir (#3934)

Reuse existing Elements code to conceal information.

---

#### Does this PR need a docs update or release note?

- [ ] ✅ Yes, it's included
- [ ] 🕐 Yes, but in a later PR
- [x] ⛔ No

#### Type of change

- [ ] 🌻 Feature
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Supportability/Tests
- [ ] 💻 CI/Deployment
- [x] 🧹 Tech Debt/Cleanup

#### Issue(s)

* #3895

#### Test Plan

- [x] 💪 Manual
- [ ] ⚡ Unit test
- [ ] 💚 E2E

src/pkg/path/elements.go

@@ -2,7 +2,6 @@ package path
 
 import (
 	"fmt"
-	"strings"
 
 	"github.com/alcionai/clues"
 
@@ -119,16 +118,8 @@ func (el Elements) Last() string {
 // LoggableDir takes in a path reference (of any structure) and conceals any
 // non-standard elements (ids, filenames, foldernames, etc).
 func LoggableDir(ref string) string {
-	r := ref
-	n := strings.TrimSuffix(r, string(PathSeparator))
-
-	for n != r {
-		r = n
-		n = strings.TrimSuffix(r, string(PathSeparator))
-	}
-
-	elems := Split(r)
-	elems = pii.ConcealElements(elems, piiSafePathElems)
-
-	return join(elems)
+	// Can't directly use Builder since that could return an error. Instead split
+	// into elements and use that.
+	split := Split(TrimTrailingSlash(ref))
+	return Elements(split).Conceal()
 }