P3 collisions

[rorlija1]

• PR with geometric collision kernel between ice and liquid particles.
• Also attempted to implement collisions in src, but I have many doubts... I also did not have the chance to add any docs for collisions... see my comments and ask me anything! I used some of Anastasia's old code but changed/added things from MM2015, Cholette 2019, and Musil 1970 (a paper they reference).
• The rates run in KiD but very very slowly...

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 96.81%. Comparing base (05e2b1c) to head (4de3a31). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #442 +/- ## ======================================= Coverage 96.80% 96.81% ======================================= Files 41 41 Lines 1442 1445 +3 ======================================= + Hits 1396 1399 +3 Misses 46 46 ``` | [Components](https://app.codecov.io/gh/CliMA/CloudMicrophysics.jl/pull/442/components?src=pr&el=components&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=CliMA) | Coverage Δ | | |---|---|---| | [src](https://app.codecov.io/gh/CliMA/CloudMicrophysics.jl/pull/442/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=CliMA) | `98.73% <100.00%> (+<0.01%)` | :arrow_up: | | [ext](https://app.codecov.io/gh/CliMA/CloudMicrophysics.jl/pull/442/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=CliMA) | `69.79% <ø> (ø)` | |