Update xsl to the latest through all platforms and update readme

• Updated XSLT templates to the latest versions across all platforms (e.g., Jenkins, Azure DevOps...).
• Updated the lowest supported version of dottest in the README. I updated it according to the introduction section in the documentation of Parasoft Findings (e.g. https://docs.parasoft.com/display/FINDS/Parasoft+Findings+for+Jenkins#ParasoftFindingsforJenkins-Introduction)
  • Question:
    • For integration with GitLab, we started to include it in the dottest documentation since version 2021.2 (https://docs.parasoft.com/display/DOTTEST20212/Integrating+with+GitLab), and we only did documentation for static analysis reports. Should we update the documentation for all versions from 2020.2+ to include GitLab support for unit tests and coverage?