shared: split out UID allocation range stuff from user-record.h

user-record.[ch] are about the UserRecord JSON stuff, and the UID
allocation range stuff (i.e. login.defs handling) is a very different
thing, and complex enough on its own, let's give it its own c/h files.

No code changes, just some splitting out of code.

src/test/test-condition.c

@@ -32,7 +32,7 @@
 #include "strv.h"
 #include "tests.h"
 #include "tomoyo-util.h"
-#include "user-record.h"
+#include "uid-alloc-range.h"
 #include "user-util.h"
 #include "virt.h"
 

src/test/test-user-record.c

@@ -7,9 +7,9 @@
 #include "fileio.h"
 #include "format-util.h"
 #include "fs-util.h"
-#include "tmpfile-util.h"
 #include "tests.h"
-#include "user-record.h"
+#include "tmpfile-util.h"
+#include "uid-alloc-range.h"
 
 static void test_read_login_defs(const char *path) {
         log_info("/* %s(\"%s\") */", __func__, path ?: "<custom>");