lib: create a clock class object from component

lib: create a clock class object from component

Before this commit, a trace class was needed for the creation of a clock
class. Turns out that clock class may be needed before the creation any
trace class. For example, Inactivity messages created before a trace has
generated any data need a clock class but no trace class was created yet.

This commit allows for the creation of clock classes even when no trace
classes exist using a component class.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>