Test coverage reports + improvements

[ArchibaldBienetre]

• [x] Add JaCoCo or another test coverage runner to the build + run it on CI
  • https://docs.gradle.org/current/userguide/jacoco_plugin.html
• [x] Add test coverage HTML reports to the CI output
• [x] Add a dedicated test to cover all parts of the regex in org.example.csv2tex.rendering.SchoolReportsRenderer.java#moveAllTexFilesInSameFolderToTemporaryDirectory
• [x] Complete test coverage for all CSV parsing exceptions
  • for reference, this is the current coverage report (HTML + style, zipped): coverage_CsvValidator.java.zip

[ArchibaldBienetre]

I'll wait for a few pull requests to get merged before I continue - I want to avoid any merge conflicts

EDIT: :heavy_check_mark:

[ArchibaldBienetre]

This is the last issue that is missing for the 1.1.0 release https://github.com/SergelsOrg/csv2tex/releases/edit/untagged-ccfa0d4694a458ee2170

[ArchibaldBienetre]

Last pull request is in the works now (finally, sorry for this huge delay) https://github.com/SergelsOrg/csv2tex/pull/108