Add 2 compartment PK model

[DavAug]

• Adds clearance parametrisation for 1 compartment PK model
• Adds 2 compartment PK model

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.93%. Comparing base (b3de6c9) to head (2003e9f).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #279   +/-   ##
=======================================
  Coverage   99.93%   99.93%           
=======================================
  Files          18       18           
  Lines        4310     4317    +7     
=======================================
+ Hits         4307     4314    +7     
  Misses          3        3           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.