Fix plural/singular for flags (#1230)

## Description

Unify plural/singular for flags

## Type of change

<!--- Please check the type of change your PR introduces: --->
- [ ] 🌻 Feature
- [x] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Test
- [ ] 💻 CI/Deployment
- [ ] 🐹 Trivial/Minor

## Issue(s)

<!-- Can reference multiple issues. Use one of the following "magic words" - "closes, fixes" to auto-close the Github issue. -->

## Test Plan

<!-- How will this be tested prior to merging.-->
- [x] 💪 Manual
- [ ] ⚡ Unit test
- [ ] 💚 E2E

src/cli/utils/exchange.go

@@ -8,11 +8,11 @@ import (
 
 // flag names
 const (
-	ContactFN             = "contacts"
+	ContactFN             = "contact"
 	ContactFolderFN       = "contact-folder"
 	EmailFN               = "email"
 	EmailFolderFN         = "email-folder"
-	EventFN               = "events"
+	EventFN               = "event"
 	EventCalendarFN       = "event-calendar"
 	ContactNameFN         = "contact-name"
 	EmailReceivedAfterFN  = "email-received-after"

src/cli/utils/onedrive.go

@@ -8,9 +8,9 @@ import (
 
 const (
 	FileFN               = "file"
-	FolderFN             = "folders"
+	FolderFN             = "folder"
-	NamesFN              = "names"
+	NamesFN              = "name"
-	PathsFN              = "paths"
+	PathsFN              = "path"
 	FileCreatedAfterFN   = "file-created-after"
 	FileCreatedBeforeFN  = "file-created-before"
 	FileModifiedAfterFN  = "file-modified-after"