feat add admin user get detail info

Author: kwonhee1

src/main/java/NextLevel/demo/admin/user/AdminUserController.java

@@ -27,6 +27,11 @@ public ResponseEntity getUserList(Pageable pageable) {
         return ResponseEntity.ok().body(new SuccessResponse("success", adminUserService.getUserList(pageable)));
     }
 
+    @GetMapping("/{userId}")
+    public ResponseEntity getUserInfo(@PathVariable("userId") Long userId) {
+        return ResponseEntity.ok().body(new SuccessResponse("success", adminUserService.getUserInfo(userId)));
+    }
+
     public ResponseEntity stopUser() {
         return null;
     }

src/main/java/NextLevel/demo/admin/user/AdminUserService.java

@@ -29,6 +29,11 @@ public List<ResponseUserInfoDetailDto> getUserList(Pageable pageable) {
         return userRepository.findAll(pageable).stream().map(ResponseUserInfoDetailDto::of).toList();
     }
 
+    public ResponseUserInfoDetailDto getUserInfo(Long userId) {
+        UserEntity user = userValidateService.findUserWithUserId(userId);
+        return ResponseUserInfoDetailDto.of(user);
+    }
+
     public void stopUser() {
         // not yet
     }