Validate dimensions and crop offsets in H.264 SPS parser

Add bounds checking in SpsParser to prevent arithmetic overflow and
underflow when calculating picture dimensions and crop offsets:
- Validate chroma_format_idc (<= 3) and pic_order_cnt_type (<= 2).
- Compute uncropped dimensions using 64-bit arithmetic and verify
  they do not exceed uint16_t limits.
- Ensure total crop offsets do not equal or exceed uncropped dimensions,
  preventing underflow and zero or negative picture sizes.
- Return std::nullopt on malformed parameters.

Bug: chromium:516683896
Change-Id: Ib405c094f9d7b568f436033bd356039ace1104df
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/500603
Reviewed-by: Sergey Silkin <ssilkin@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#48515}