Fix integer overflow in image decoders

[nidu-ninja]

Fix multiple integer overflow/underflow issues in image decoders (TIFF, CCITT, BMP)

Replaced unchecked arithmetic with Checked in several parsing paths to prevent wraparound in size and row calculations. Malformed inputs could previously trigger large allocations or out-of-bounds behavior.

Adds regression tests covering malformed TIFF (strip count mismatch, CCITT dimensions) and BMP RLE buffer size overflow cases.

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[LucasChollet]

Thanks for fixing these. The test cases are missing though.

[nidu-ninja]

Thanks for fixing these. The test cases are missing though.

i have added the flies