On jazzy the released openvdb version is already 10.0.1, so we don't
have to compile the vendor package.

Compilation on the build farm was already quite flakey because the
package is quite heavy, so I'd be best to avoid this. I don't know if
openvdb is also released for ARM or any other ubuntu platforms, but
we'll have to see on the buildfarm.

The cmake module was located in another folder.

Signed-off-by: Steve Macenski <stevenmacenski@gmail.com>

* last_updated_ is now not updated on reset(), and observation staleness is now determined by comparison to clock_->now() instead of the last observation.

* Readded the observation buffer update on reset.

* Used correct whitespace again

Signed-off-by: Steve Macenski <stevenmacenski@gmail.com>