The archive-get command is implemented entirely in C.

This new implementation should behave exactly like the old Perl code with the exception of a few updated log messages.

Remove as much of the Perl code as possible without breaking other commands.

doc/xml/user-guide.xml

@@ -2975,7 +2975,7 @@
                 </execute>
                 <execute user="postgres" output="y">
                     <exe-cmd>cat /var/log/pgbackrest/demo-archive-get-async.log</exe-cmd>
-                    <exe-highlight>got WAL file [0-F]{24} from archive</exe-highlight>
+                    <exe-highlight>found [0-F]{24} in the archive</exe-highlight>
                 </execute>
             </execute-list>
         </section>