Remove some deprecated functions

[rdeits]

On top of #141

• Removes the old (pre-Cassette)-style animation atframe method
• Removes HyperCylinder, which has been a deprecated alias for Cylinder for a long time

[codecov-io]

Codecov Report

Merging #143 into master will increase coverage by 2.21%.
The diff coverage is 55.17%.

@@            Coverage Diff             @@
##           master     #143      +/-   ##
==========================================
+ Coverage   79.27%   81.48%   +2.21%     
==========================================
  Files          15       18       +3     
  Lines         468      470       +2     
==========================================
+ Hits          371      383      +12     
+ Misses         97       87      -10

Impacted Files	Coverage Δ
src/geometry.jl	100% <ø> (ø)	⬆️
src/atframe.jl	87.09% <ø> (+1.8%)	⬆️
src/lowering.jl	98.48% <ø> (+8.2%)	⬆️
src/commands.jl	83.33% <ø> (+11.9%)	⬆️
src/assets.jl	0% <0%> (ø)
src/servers.jl	4% <0%> (-0.55%)	⬇️
src/integrations.jl	100% <100%> (ø)
src/MeshCat.jl	80% <100%> (+46.66%)	⬆️
src/render.jl	33.33% <33.33%> (ø)
src/visualizer.jl	91.42% <90.69%> (+15.37%)	⬆️
... and 3 more

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