Parser: Round float attributes to check validity

[youknowriad]

When resizing images, they receive a float "height/width" values and these values might defer a bit when the post is saved server side because of the PHP default precision which would cause the image block to appear invalid if you refresh

This PR updates the attributes comparison mechanism to round float attributes before comparing them.

Testing instructions

• Create an image block
• Resize the image
• Save and refresh
• The block shouldn't show up as invalid
• Repeat several times :)

[codecov]

Codecov Report

Merging #3494 into master will increase coverage by 0.04%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #3494      +/-   ##
==========================================
+ Coverage   34.63%   34.68%   +0.04%     
==========================================
  Files         260      260              
  Lines        6738     6741       +3     
  Branches     1219     1219              
==========================================
+ Hits         2334     2338       +4     
+ Misses       3718     3717       -1     
  Partials      686      686

Impacted Files	Coverage Δ
blocks/api/validation.js	96.92% <100%> (+1.76%)	⬆️

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[jorgefilipecosta]

I tested this with many case in images resized to very very small sizes with float sizes in height and I did not found any regression. The code also looks good to me. So I think this is ok to be merged.
But I think it would be ok to round the values to integer sizes, we are talking about pixels so I think using float values is not needed.

[youknowriad]

closing this and going with #3495 for now. We should avoid recreating the block comments server-side in the future.