Create helper function to go from service type to metadata service type (#5091)

Will also be used more in later PRs

---

#### 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

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

#### Test Plan

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

src/pkg/path/builder.go

@@ -232,18 +232,7 @@ func (pb Builder) ToStreamStorePath(
 		return nil, clues.New("missing path beyond prefix")
 	}
 
-	metadataService := UnknownService
-
-	switch service {
-	case ExchangeService:
-		metadataService = ExchangeMetadataService
-	case OneDriveService:
-		metadataService = OneDriveMetadataService
-	case SharePointService:
-		metadataService = SharePointMetadataService
-	case GroupsService:
-		metadataService = GroupsMetadataService
-	}
+	metadataService := service.ToMetadata()
 
 	return &dataLayerResourcePath{
 		Builder: *pb.withPrefix(
@@ -275,18 +264,7 @@ func (pb Builder) ToServiceCategoryMetadataPath(
 		return nil, clues.New("missing path beyond prefix")
 	}
 
-	metadataService := UnknownService
-
-	switch service {
-	case ExchangeService:
-		metadataService = ExchangeMetadataService
-	case OneDriveService:
-		metadataService = OneDriveMetadataService
-	case SharePointService:
-		metadataService = SharePointMetadataService
-	case GroupsService:
-		metadataService = GroupsMetadataService
-	}
+	metadataService := service.ToMetadata()
 
 	rp := dataLayerResourcePath{
 		Builder: *pb.withPrefix(

src/pkg/path/service_category_test.go

@@ -187,3 +187,37 @@ func (suite *ServiceCategoryUnitSuite) TestToCategoryType() {
 		})
 	}
 }
+
+func (suite *ServiceCategoryUnitSuite) TestToMetadata() {
+	table := []struct {
+		input  ServiceType
+		expect ServiceType
+	}{
+		{
+			input:  ExchangeService,
+			expect: ExchangeMetadataService,
+		},
+		{
+			input:  OneDriveService,
+			expect: OneDriveMetadataService,
+		},
+		{
+			input:  SharePointService,
+			expect: SharePointMetadataService,
+		},
+		{
+			input:  GroupsService,
+			expect: GroupsMetadataService,
+		},
+		{
+			input:  UnknownService,
+			expect: UnknownService,
+		},
+	}
+
+	for _, test := range table {
+		suite.Run(test.input.String(), func() {
+			assert.Equal(suite.T(), test.expect, test.input.ToMetadata())
+		})
+	}
+}

src/pkg/path/service_type.go

@@ -74,3 +74,18 @@ func (svc ServiceType) HumanString() string {
 
 	return "Unknown Service"
 }
+
+func (svc ServiceType) ToMetadata() ServiceType {
+	switch svc {
+	case ExchangeService:
+		return ExchangeMetadataService
+	case OneDriveService:
+		return OneDriveMetadataService
+	case SharePointService:
+		return SharePointMetadataService
+	case GroupsService:
+		return GroupsMetadataService
+	}
+
+	return UnknownService
+}