Error callback function for RgbaInputFile

It would be nice if we could override the error callback handler for RgbaInputFile.
The default error callback dumps error messages on stderr and that might be undesirable.
For most of the InputFile classes it is already possible to set custom error callback by constructing with ContextInitializer, for example:
` MultiPartInputFile ifile(
fileName,
ContextInitializer()
.silentHeaderParse (true)
.strictHeaderValidation (false)
.disableChunkReconstruction(false)
.setErrorHandler(customExrErrorHandlerCb)
);
`
Such constructor is not implemented for RgbaInputFile, AcesInputFile and possibly other classes.

Start by inspecting the RgbaInputFile and AcesInputFile constructors and compare them with the MultiPartInputFile ContextInitializer example in the issue. Trace how setErrorHandler is passed to other InputFile classes, then verify that a custom callback can replace the default stderr output without changing existing behavior.

Written by the indexing model from the issue text.