shared: move psi-util.[ch] to basic/ so that we can use it in sd-event

src/basic/meson.build

@@ -65,6 +65,7 @@ basic_sources = files(
         'proc-cmdline.c',
         'process-util.c',
         'procfs-util.c',
+        'psi-util.c',
         'random-util.c',
         'ratelimit.c',
         'recurse-dir.c',

src/shared/meson.build

@@ -123,7 +123,6 @@ shared_sources = files(
         'pcre2-util.c',
         'pkcs11-util.c',
         'pretty-print.c',
-        'psi-util.c',
         'ptyfwd.c',
         'pwquality-util.c',
         'qrcode-util.c',