- CuasRTUtils: add convolve3d(data, Rectangle roi, result_in) that allocates
  only [roi.width*roi.height][nsub][nvel] instead of full [width*height][nsub][nvel],
  skips non-ROI pixels in center/margin loops, uses roi-relative indexing.
  Also fix showConvKernel5d(data, roi, ...) pixel_idx to use ROI-relative
  (py_roi*roi.width+px_roi) instead of full-image indexing.

- CuasDetectRT: add dpixels_5d_roi_pyramid alongside dpixels_5d_pyramid.
  Level-0 and pyramid loop 5D blocks now call convolve3d(window, null) only
  when curt_save_c5full, and convolve3d(window, curt_save_select, null) only
  when curt_save_c5rect. RECT save blocks now read from dpixels_5d_roi_pyramid.
  Eliminates the OutOfMemoryError when curt_save_c5full=false.
Co-authored-by: Claude <claude@elphel.com>