Using the environment's path to find covoar allow invalid versions
to be used which may vary in subtle ways. Find and use the covoar
that is build with the version of 'rtems-test'.
This patch means you do not need to install the tools before
running improving the development experience.
Closes#3458
Add support in tester to run covoar and generate an html report to display
the summary of the coverage reports generated from covoar.
Co-authored-by : Cillian O'Donnell <cpodonnell8@gmail.com>
