Fix: Export inplaceConvertFrame* functions for shared library build

- Added CCAP_EXPORT to inplaceConvertFrame(), inplaceConvertFrameRGB(), and inplaceConvertFrameYUV2RGBColor()
- Fixes LNK2019 unresolved external symbol error in Debug-shared build configuration
- Required for test_frame_conversions.cpp to link correctly with shared library

Author: wysaid

src/ccap_convert_frame.h

@@ -32,9 +32,9 @@
 
 namespace ccap {
 
-bool inplaceConvertFrame(VideoFrame* frame, PixelFormat toFormat, bool verticalFlip);
-bool inplaceConvertFrameRGB(VideoFrame* frame, PixelFormat toFormat, bool verticalFlip);
-bool inplaceConvertFrameYUV2RGBColor(VideoFrame* frame, PixelFormat toFormat, bool verticalFlip);
+CCAP_EXPORT bool inplaceConvertFrame(VideoFrame* frame, PixelFormat toFormat, bool verticalFlip);
+CCAP_EXPORT bool inplaceConvertFrameRGB(VideoFrame* frame, PixelFormat toFormat, bool verticalFlip);
+CCAP_EXPORT bool inplaceConvertFrameYUV2RGBColor(VideoFrame* frame, PixelFormat toFormat, bool verticalFlip);
 
 } // namespace ccap