Implement CTF-IR Clock getters

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Tests: Test CTF-IR Clock's getters

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Add Python bindings for CTF-IR clock's getters

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Implement CTF-IR event-fields getters

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>