Add script “passusermenu”

Add the script “passusermenu” to provide the same functionality as the
“passmenu” script but copying the username using the “pass-user” plugin.

passusermenu

@@ -0,0 +1,17 @@
+#!/bin/sh
+set -e
+shopt -s nullglob globstar
+
+# Present menu to select password
+prefix=${PASSWORD_STORE_DIR-~/.password-store}
+password_files=( "$prefix"/**/*.gpg )
+password_files=( "${password_files[@]#"$prefix"/}" )
+password_files=( "${password_files[@]%.gpg}" )
+password=$(printf '%s\n' "${password_files[@]}" | bemenu $@)
+
+# Copy password to clipboard
+pass user "$password" 2>/dev/null
+
+# Send notification
+notify-send -u critical -t 45000 "Username in clipboard" \
+    "The username for \"$password\" is currently in the clipboard."