Resolve "xs:list deserialization does not split on all whitespace"

[JGM01]

Changed DELIMITER (u8) into an array DELIMITERS (u8; 4) that holds 4 possible delimiters.

This was implemented with issue #839 in mind, so I covered the following whitespaces: , \t, \r, \n. It is fairly easy to include more if necessary.

[Mingun]

Thanks for PR. I would like to have:

• a new test that ensures that bug is fixed
• a changelog entry informing users that bug is fixed

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 60.56%. Comparing base (a9391f3) to head (b86f89a).
Report is 26 commits behind head on master.

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #843      +/-   ##
==========================================
+ Coverage   60.21%   60.56%   +0.35%     
==========================================
  Files          41       41              
  Lines       16021    15951      -70     
==========================================
+ Hits         9647     9661      +14     
+ Misses       6374     6290      -84     

Flag	Coverage Δ
unittests	60.56% <100.00%> (+0.35%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.