Change the way test case UUID is passed to rich-core-dumper

A file with UUID is now created in rich-core-dumper's output directory.
This approach doesn't require root privileges unlike manipulating
kernel.core_pattern.
Rename td_file_delete -> td_file_delete_link
Add td_file_delete()
Collect URLs of rich cores uploaded by crash-reporter
Wait for core uploads to finish
Add configurable crash report upload timeout