Merge pull request #27811 from Kumataro:fix27789

imgcodecs: bmp: relax decoding size limit to over 1GiB #27811

Close https://github.com/opencv/opencv/issues/27789
Close https://github.com/opencv/opencv/issues/23233

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [x] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake

modules/imgcodecs/src/utils.cpp

@@ -51,6 +51,13 @@ int validateToInt(size_t sz)
     return valueInt;
 }
 
+int64_t validateToInt64(size_t sz)
+{
+    int64_t valueInt = static_cast<int64_t>(sz);
+    CV_Assert((size_t)valueInt == sz);
+    return valueInt;
+}
+
 #define  SCALE  14
 #define  cR  (int)(0.299*(1 << SCALE) + 0.5)
 #define  cG  (int)(0.587*(1 << SCALE) + 0.5)