Transpose images when reading/writing images

[notZaki]

While going back and forth between Julia and an external dicom viewer, I've noticed that the images are always transposed in Julia.
This is likely because Julia's arrays are column-major while dicom's pixel arrays are row-major.
The solution was to permute the first two dimensions, and this seems to be working well.

A special case was added for interleaved images, i.e. those with (0x0028, 0x0006) Planar Configuration = 0. These weren't fully supported before, but they should now be properly parsed.
However, these images will still not be written correctly unless Planar Configuration is set to 1.

(Unrelated: a few tags/fields for animal scans were also added.)

I will merge this early next week if there aren't any objections.

[codecov]

Codecov Report

Merging #39 into master will decrease coverage by 0.15%.
The diff coverage is 86.66%.

@@            Coverage Diff             @@
##           master      #39      +/-   ##
==========================================
- Coverage   88.97%   88.81%   -0.16%     
==========================================
  Files           1        1              
  Lines         272      286      +14     
==========================================
+ Hits          242      254      +12     
- Misses         30       32       +2

Impacted Files	Coverage Δ
src/DICOM.jl	88.81% <86.66%> (-0.16%)	⬇️

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