Add files that are generated by 'make examples' and remove some that
have been renamed.
The commits that renamed the programs are
e9625c5bc6c046a (imap.c and
simplesmtp.c were renamed to imap-fetch.c and smtp-send.c) and
ad39e7ec01e7 (pop3slist.c and pop3s.c were renamed to pop3-list.c and
pop3-ssl.c).
Closes #6240
10-at-a-time
+altsvc
anyauthput
certinfo
chkspeed
http2-pushinmemory
http2-serverpush
http2-upload
+http3
+http3-present
httpcustomheader
httpput
+httpput-postfields
https
-imap
imap-append
+imap-authzid
imap-copy
imap-create
imap-delete
multi-debugcallback
multi-double
multi-formadd
+multi-poll
multi-post
multi-single
parseurl
persistent
+pop3-authzid
pop3-dele
pop3-list
pop3-multi
pop3-tls
pop3-top
pop3-uidl
-pop3s
-pop3slist
post-callback
postinmemory
postit2
shared-connection-cache
simple
simplepost
-simplesmtp
simplessl
+smtp-authzid
smtp-expn
smtp-mail
smtp-mime