Switch dprint_r and dieprint_r to Keruald\OmniTools\Debugger

Summary:
This is a follow-up for change c7e86b370905.

This change uses the general method, and not the registration
feature offered by omnitools to populate global space.

Ref T1395.

Test Plan:

use function Keruald\dprint_r;
use function Keruald\dieprint_r;

dprint_r($someVariable);
dieprint_r($someVvariable);

Reviewers: dereckson

Reviewed By: dereckson

Maniphest Tasks: T1395

Differential Revision: https://devcentral.nasqueron.org/D1622