add support to upload test reports in xml format

[jnadal-klg]

my use case:
wanted to upload separate test reports and separate coverage test reports for flutter unit tests and patrol based e2e tests. Patrol will generate native platform reports: for android, i can get xml/html reports.

I can generate flutter test reports, and import them into sonarqube using sonar.flutter.tests.reportPath and dart_test.yaml, i can see the test count on the project overview tab next to code coverage.
I can generate lcov.info coverage file for the unit tests.
i can generate e2e test report in the native xml format of the android platform (i can see a TEST-*.xml file under build/app/outputs/androidTest-results/connected), but there is no easy / documented way to either generate the report in the same json format as the flutter tests, nor i can find any tool for converting from xml to this json like format.
I can generate coverage reports for e2e tests in lcov format on a separate file. Then merge both coverage reports into a single file using lcov and upload it to sonarqube. I can see the coverage data changing, so i'm certain this works.

In short i just need either the ability to upload e2e tests report in xml format, or a link to some tool that allows me to convert the xml into something that the plugin will accept on the sonar.flutter.tests.reportPath or some indications to configure patrol/android to generate the reports in the json like format instead of xml/html.

also, since there is already support for multiple files on the sonar.flutter.tests.reportPath, i would also like to be allowed to upload multiple files on sonar.flutter.coverage.reportPath, that would eliminate the need to merge lcov files before uploading