fix(postcss-svgo): normalize SVG with escaped quote characters

[IronGeek]

Fixes #1194

[codecov-commenter]

Codecov Report

Merging #1200 (354d331) into master (3a1410e) will increase coverage by 0.00%.
The diff coverage is 100.00%.

❗ Current head 354d331 differs from pull request most recent head 5e22295. Consider uploading reports for the commit 5e22295 to get more accurate results

@@           Coverage Diff           @@
##           master    #1200   +/-   ##
=======================================
  Coverage   96.56%   96.57%           
=======================================
  Files         117      117           
  Lines        3644     3646    +2     
  Branches     1071     1071           
=======================================
+ Hits         3519     3521    +2     
  Misses        117      117           
  Partials        8        8           

Impacted Files	Coverage Δ
packages/postcss-svgo/src/index.js	100.00% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 3a1410e...5e22295. Read the comment docs.

[ludofischer]

It does seem to fix this problem, but I wonder whether this is an issue with postcss-value-parser. Is css-value-parser supposed to return the escape characters? @alexander-akait any thoughts?

[alexander-akait]

@ludofischer hm, look like something broken, ideally parser should return { string: "normalized-value", rawString: "real-value" } and we should use rawString... We can merge it here, but will be great to fix it in parser

[ludofischer]

Since we could not fix this in the parser in the last 18 days, I think I am going to merge this, so at least we've got the test cases.