Initial commit: Logo detection test framework

Add DETR+CLIP based logo detection library and test framework:
- DetectLogosDETR class for logo detection and matching
- Test script with margin-based and multi-ref matching methods
- Data preparation script for test database
- Documentation for API usage and test methodology

main.py

@@ -0,0 +1,6 @@
+def main():
+    print("Hello from logo-test!")
+
+
+if __name__ == "__main__":
+    main()