Remove numeric PK models.

Summary:
Remove numerical 2CXM from MR Perfusion View.

Remove numeric Two Tissue Compartment Model from PET Dynamic View

Remove 2CXM from Perfusion Data Simulation View.

Remove all components of the numeric 2CXM from the Pharmacokinetics module.

Remove all components of the Numeric Two Tissue Compartment Model from the Pharmacokinetics module.

Test Plan: Manual

Reviewers: floca, O3 MITK Reviewer Group II

Reviewed By: floca, O3 MITK Reviewer Group II

Differential Revision: https://phabricator.mitk.org/D868