Rename statedump and dl events and fields

The current names of the `lttng_ust_statedump:soinfo` event, as well
as its field `sopath` both refer exclusively to shared objects (so),
although the event applies to any executables, including
position-independent executables (PIE), as well as shared objects.

Thus, this patch changes the name of the event to `bin_info` and the
field to `path`, to avoid any confusion.

For consistency, the `sopath` field in the `lttng_ust_dl:dlopen` event
is also renamed to `path`, although dlopen only applies to shared
objects.

Signed-off-by: Antoine Busque <abusque@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>