[MM-54770] Add ability to export profile pictures and fix importing them (#25042)

* add ability to export pp and fix import

* remove unused nopSeeker

* remove debug log

* fix shadow vars

* generate a warning instead of an error when unable to export profile picture

* fix merge conflicts

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Co-authored-by: Mattermost Build <build@mattermost.com>

server/cmd/mmctl/docs/mmctl_export_create.rst

@@ -22,6 +22,7 @@ Options
 
   -h, --help                        help for create
       --include-archived-channels   Include archived channels in the export file.
+      --include-profile-pictures    Include profile pictures in the export file.
       --no-attachments              Exclude file attachments from the export file.
 
 Options inherited from parent commands