CLI: Add commands to handle attachments

* Add commands to manipulate entry attachments from the CLI
* Closes #4462

* Add the following commands:
  attachment-export: Exports the content of an attachment to a specified file.

  attachment-import: Imports the attachment into an entry. An existing attachment with the same name may be overwritten if the -f option is specified.

  attachment-rm: Removes the named attachment from an entry.

* Add --show-attachments  to the show command

1 files changed, 3 insertions, 0 deletions

diff --git a/tests/TestCli.h b/tests/TestCli.h
index 299264dd7..bbe80a4b3 100644
--- a/tests/TestCli.h
+++ b/tests/TestCli.h
@@ -47,6 +47,9 @@ private slots:
     void testAdd();
     void testAddGroup();
     void testAnalyze();
+    void testAttachmentExport();
+    void testAttachmentImport();
+    void testAttachmentRemove();
     void testClip();
     void testCommandParsing_data();
     void testCommandParsing();