Issue 2022 eventincr (#2167)

## Description

Fixes and unskips the tests incremental integration tests
for exchange calendar events.

Currently blocked on LynneR displaying the calendar
fetch issues where it's only possible to retrieve her default
Calendar, Birthdays, and US Holidays calendars.

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

- [x] ⛔ No 

## Type of change

- [x] 🤖 Test

## Issue(s)

* #2022

## Test Plan

- [x] 💪 Manual
- [x] 💚 E2E

src/internal/operations/backup_integration_test.go

@@ -643,8 +643,7 @@ func (suite *BackupOpIntegrationSuite) TestBackup_Run_exchangeIncrementals() {
 		categories = map[path.CategoryType][]string{
 			path.EmailCategory:    exchange.MetadataFileNames(path.EmailCategory),
 			path.ContactsCategory: exchange.MetadataFileNames(path.ContactsCategory),
-			// TODO: not currently functioning; cannot retrieve generated calendars
-			// path.EventsCategory:   exchange.MetadataFileNames(path.EventsCategory),
+			path.EventsCategory:   exchange.MetadataFileNames(path.EventsCategory),
 		}
 		container1      = fmt.Sprintf("%s%d_%s", incrementalsDestContainerPrefix, 1, now)
 		container2      = fmt.Sprintf("%s%d_%s", incrementalsDestContainerPrefix, 2, now)
@@ -715,14 +714,13 @@ func (suite *BackupOpIntegrationSuite) TestBackup_Run_exchangeIncrementals() {
 				container2: {},
 			},
 		},
-		// TODO: not currently functioning; cannot retrieve generated calendars
-		// path.EventsCategory: {
-		// 	dbf: eventDBF,
-		// 	dests: map[string]contDeets{
-		// 		container1: {},
-		// 		container2: {},
-		// 	},
-		// },
+		path.EventsCategory: {
+			dbf: eventDBF,
+			dests: map[string]contDeets{
+				container1: {},
+				container2: {},
+			},
+		},
 	}
 
 	// populate initial test data
@@ -775,6 +773,7 @@ func (suite *BackupOpIntegrationSuite) TestBackup_Run_exchangeIncrementals() {
 	sel.Include(
 		sel.MailFolders(containers, selectors.PrefixMatch()),
 		sel.ContactFolders(containers, selectors.PrefixMatch()),
+		sel.EventCalendars(containers, selectors.PrefixMatch()),
 	)
 
 	bo, _, kw, ms, closer := prepNewTestBackupOp(t, ctx, mb, sel.Selector, ffs)
@@ -883,8 +882,8 @@ func (suite *BackupOpIntegrationSuite) TestBackup_Run_exchangeIncrementals() {
 					dataset[category].dests[container3] = contDeets{id, deets}
 				}
 			},
-			itemsRead:    4,
-			itemsWritten: 4,
+			itemsRead:    6, // two items per category
+			itemsWritten: 6,
 		},
 		{
 			name: "rename a folder",
@@ -934,8 +933,8 @@ func (suite *BackupOpIntegrationSuite) TestBackup_Run_exchangeIncrementals() {
 					}
 				}
 			},
-			itemsRead:    0,
-			itemsWritten: 4,
+			itemsRead:    2,
+			itemsWritten: 8, // two items per category
 		},
 		{
 			name: "add a new item",
@@ -971,8 +970,8 @@ func (suite *BackupOpIntegrationSuite) TestBackup_Run_exchangeIncrementals() {
 					}
 				}
 			},
-			itemsRead:    2,
-			itemsWritten: 2,
+			itemsRead:    3, // one item per category
+			itemsWritten: 3,
 		},
 		{
 			name: "delete an existing item",
@@ -1003,12 +1002,12 @@ func (suite *BackupOpIntegrationSuite) TestBackup_Run_exchangeIncrementals() {
 						require.NoError(t, err, "getting event ids")
 						require.NotEmpty(t, ids, "event ids in folder")
 
-						err = cli.CalendarsById(ids[0]).Delete(ctx, nil)
+						err = cli.EventsById(ids[0]).Delete(ctx, nil)
 						require.NoError(t, err, "deleting calendar: %s", support.ConnectorStackErrorTrace(err))
 					}
 				}
 			},
-			itemsRead:    2,
+			itemsRead:    3, // one item per category
 			itemsWritten: 0, // deletes are not counted as "writes"
 		},
 	}
@@ -1035,9 +1034,9 @@ func (suite *BackupOpIntegrationSuite) TestBackup_Run_exchangeIncrementals() {
 			)
 
 			// do some additional checks to ensure the incremental dealt with fewer items.
-			// +4 on read/writes to account for metadata: 1 delta and 1 path for each type.
-			assert.Equal(t, test.itemsWritten+4, incBO.Results.ItemsWritten, "incremental items written")
-			assert.Equal(t, test.itemsRead+4, incBO.Results.ItemsRead, "incremental items read")
+			// +6 on read/writes to account for metadata: 1 delta and 1 path for each type.
+			assert.Equal(t, test.itemsWritten+6, incBO.Results.ItemsWritten, "incremental items written")
+			assert.Equal(t, test.itemsRead+6, incBO.Results.ItemsRead, "incremental items read")
 			assert.NoError(t, incBO.Results.ReadErrors, "incremental read errors")
 			assert.NoError(t, incBO.Results.WriteErrors, "incremental write errors")
 			assert.Equal(t, 1, incMB.TimesCalled[events.BackupStart], "incremental backup-start events")