tests/tracing: add trace type feature tests

tests/tracing: add trace type feature tests

This patch adds a new tracing test category named `counter-clock`.

This is because the `counter-clock` platform (in
`tests/tracing/support/counter-clock`) has a data stream clock which is
a simpler counter starting at 0.

The platform's base YAML trace type object,
`tests/tracing/support/counter-clock/base.yaml`, specifies a single
event record type `dummy` so that test-specific configurations which do
not need event record types are lighter.

The C files in `tests/tracing/src/counter-clock/trace-type-features`
do not call any tracing function: they only initialize and finalize
the test platform, which effectively opens and closes a single packet.

In the new `test-platform.c` file, test_platform_fini() closes the
current packet whether or not it's empty.

`tests/tracing/support/counter-clock/base-no-features.yaml` is a YAML
trace type object file which disables all the trace type and data stream
type features except the data stream type ID and event record type ID
features.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>