log failure cause on purge (#1307)

## Description

Load tests fail on the post-test cleanup using the purge script,
but are not currently logging the cause.  Local repro has not
been successful.  This change adds additional error logging
output for review in case of failure.

## Type of change

- [x] 🤖 Test

## Issue(s)

* #902

## Test Plan

- [x] 💪 Manual

src/cmd/purge/purge.go

@@ -131,6 +131,7 @@ func handleMailFolderPurge(cmd *cobra.Command, args []string) error {
 	}
 
 	if err := runPurgeForEachUser(ctx, gc, t, purgeMailFolders); err != nil {
+		logger.Ctx(ctx).Error(err)
 		return Only(ctx, errors.Wrap(ErrPurging, "mail folders"))
 	}
 
@@ -150,6 +151,7 @@ func handleCalendarFolderPurge(cmd *cobra.Command, args []string) error {
 	}
 
 	if err := runPurgeForEachUser(ctx, gc, t, purgeCalendarFolders); err != nil {
+		logger.Ctx(ctx).Error(err)
 		return Only(ctx, errors.Wrap(ErrPurging, "event calendars"))
 	}
 
@@ -169,6 +171,7 @@ func handleContactsFolderPurge(cmd *cobra.Command, args []string) error {
 	}
 
 	if err := runPurgeForEachUser(ctx, gc, t, purgeContactFolders); err != nil {
+		logger.Ctx(ctx).Error(err)
 		return Only(ctx, errors.Wrap(ErrPurging, "contact folders"))
 	}
 
@@ -188,6 +191,7 @@ func handleOneDriveFolderPurge(cmd *cobra.Command, args []string) error {
 	}
 
 	if err := runPurgeForEachUser(ctx, gc, t, purgeOneDriveFolders); err != nil {
+		logger.Ctx(ctx).Error(err)
 		return Only(ctx, errors.Wrap(ErrPurging, "OneDrive folders"))
 	}
 
@@ -384,7 +388,7 @@ func purgeFolders(
 	getter func(graph.Service, string, string) ([]purgable, error),
 	deleter func(graph.Service, string, purgable) error,
 ) error {
-	Infof(ctx, "\nContainer: %s", data)
+	Infof(ctx, "Container: %s", data)
 
 	// get them folders
 	fs, err := getter(gc.Service(), uid, prefix)
@@ -417,7 +421,7 @@ func purgeFolders(
 			continue
 		}
 
-		Infof(ctx, "Deleting [%s]", displayName)
+		Infof(ctx, "∙ Deleting [%s]", displayName)
 
 		err = deleter(gc.Service(), uid, fld)
 		if err != nil {