Multiple fixes for sequential device
Changes to improve operation on sequential devices and track any regressions:
- Read test: modified to test all plugins also on a sequential device
- When a sequential device is detected, canRead() returns false if the plugin doesn't support it
- Added EXR test image and enabled the test on CMakeLists.txt
- Added PCX indexed image
The following plugins passed test on a sequential device: avif, eps, exr, hdr, heif, jxl, pic, pcx, rgb, tga.
The following plugins failed the test on a sequential device and were therefore modified: ani, kra, ora, psd, raw, xcf.
Edited by Mirco Miranda