And ignore `__pycache_` directories

Signed-off-by: Manu Bretelle <chantr4@gmail.com>

write them

This makes just easier to separate the file operations from the
generation of the content, and therefore, easier to test.

Signed-off-by: Manu Bretelle <chantr4@gmail.com>

individual test summaries

The logic between handling summaries for test and subtest was very
similar.
This function receive a (sub)test dict and generate its textual
summaries for both GH job summary and GH test console.

When asubtest is used, the parent test name and number must be passed as
arguments to the function.

Signed-off-by: Manu Bretelle <chantr4@gmail.com>