resolvectl: rename systemd-resolve to resolvectl

For the compatibility, `systemd-resolve` will be created as a symbolic
link to `resolvectl`.

src/resolve/meson.build

@@ -67,11 +67,11 @@ systemd_resolved_sources = files('''
         resolved-etc-hosts.c
 '''.split())
 
-systemd_resolve_sources = files('''
+resolvectl_sources = files('''
          resolvconf-compat.c
          resolvconf-compat.h
-         resolve-tool.c
-         resolve-tool.h
+         resolvectl.c
+         resolvectl.h
 '''.split())
 
 ############################################################

src/resolve/resolvconf-compat.c

@@ -10,7 +10,7 @@
 #include "fileio.h"
 #include "parse-util.h"
 #include "resolvconf-compat.h"
-#include "resolve-tool.h"
+#include "resolvectl.h"
 #include "resolved-def.h"
 #include "string-util.h"
 #include "strv.h"

src/resolve/resolvectl.c

@@ -24,7 +24,7 @@
 #include "pager.h"
 #include "parse-util.h"
 #include "resolvconf-compat.h"
-#include "resolve-tool.h"
+#include "resolvectl.h"
 #include "resolved-def.h"
 #include "resolved-dns-packet.h"
 #include "strv.h"