feat: ods: add style to datetime, date and time values

[pascalfree]

This solves #210 but for the ods format.

Let me know if you agree with this approach in general. I will then apply the same for datetime and time types.

Code is inspired by https://stackoverflow.com/a/28577394
I tested it with LibreOffice 7.3 so far.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.68%. Comparing base (9c82f70) to head (8189db6).
Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #594      +/-   ##
==========================================
+ Coverage   92.66%   92.68%   +0.01%     
==========================================
  Files          28       28              
  Lines        2958     2966       +8     
==========================================
+ Hits         2741     2749       +8     
  Misses        217      217              

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

[claudep]

Would you be able to add some test for that change?

I find the commit message a bit misleading, as this is fixing ods export functionality, not ods reading.

[pascalfree]

I changed the title and added tests.

The tests currently fail, because the datetime export has a bug that was previously covered by the import: #595

[claudep]

Please rebase after merge of #595

[claudep]

Thanks a lot!