feat: add P3 collision rates

[haakon-e]

Purpose

P3 collision rates (moved from #543)

Implements source terms for the P3 scheme.

• calculates the rate of collision between ice and liquid particles, numerically integrates over the size distributions, returns bulk source terms
• computes dry and wet growth rates, partitioning sources into the ice and liquid phase

To-do

• Add tests
• check docs

Content

• added function signatures
• functions return bulk source terms

---

• I have read and checked the items on the review checklist.

[haakon-e]

This change is part of the following stack:

• add supporting P3 collisions sub-parameterizations #596
  • feat: add P3 collision rates #577 ◀

_{Change managed by git-spice.}

[codecov]

Codecov Report

Attention: Patch coverage is 66.19718% with 24 lines in your changes missing coverage. Please review.

Project coverage is 91.88%. Comparing base (f98ab2c) to head (8b0f1d1).

Additional details and impacted files

@@                               Coverage Diff                               @@
##           he/feat/p3-collisions-sub-parameterizations     #577      +/-   ##
===============================================================================
- Coverage                                        92.90%   91.88%   -1.02%     
===============================================================================
  Files                                               47       47              
  Lines                                             1789     1860      +71     
===============================================================================
+ Hits                                              1662     1709      +47     
- Misses                                             127      151      +24     

Components	Coverage Δ
src	93.08% <66.19%> (-1.13%)	⬇️
ext	69.79% <ø> (ø)

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