Problem: A borked ImageDecoder could send a BitmapSequence over IPC with
metadata for a (large) bitmap while shipping a too-small backing buffer.
Decoding it produced a Gfx::Bitmap that reported the (large) geometry
but pointed at the too-small buffer — making the first write go OOB.
Cause: BitmapSequence decode reads size_in_bytes and the bitmap geometry
as independent fields, and only checked if size_in_bytes matched the
transferred buffer size — never that either is consistent with the
geometry. The single-frame fast path then handed the buffer to
Bitmap::create_with_anonymous_buffer with no verification.
Fix: Make the two bitmap factories that take externally-provided storage
enforce that it covers the geometry. create_with_anonymous_buffer now
fails with buffers smaller than the minimum expected size_in_bytes — and
create_with_raw_data similarly rejects data too small for the geometry.
Fixes https://github.com/LadybirdBrowser/ladybird/issues/10036