Make VonMises more flexible

[cscherrer]

Parameterized Trait Enhancement & VonMises Scaling Support

Summary

This PR introduces parameter structs for distributions and enhances the Parameterized trait with a default map_params implementation. It also adds scaling support for the VonMises distribution.

Changes

1. Parameter Structs

• Added parameter structs for all distributions (e.g., BernoulliParameters, GaussianParameters)
• Standardized parameter representation for better type safety and clarity
• Updated all emit_params and from_params implementations to use these structs

2. Enhanced Parameterized Trait

• Added a default map_params implementation that enables mapping functions over parameters
• This provides a consistent way to transform distribution parameters

3. VonMises Distribution Improvements

• Added Scalable trait implementation for VonMises distribution
• Added map_params implementation for efficient parameter updates
• Added from_parts_unchecked for more efficient construction

4. Data Module Enhancements

• Added extensive tests for DataOrSuffStat and categorical datum
• Fixed Scaled distribution representation by moving to eager computation of log Jacobian

Testing

Added comprehensive test coverage for all new functionality, including:

• Edge cases for categorical data
• Boolean conversions
• Parameter mapping
• VonMises scaling operations
• Additional data module validation

[codecov]

Codecov Report

Attention: Patch coverage is 62.53102% with 151 lines in your changes missing coverage. Please review.

Project coverage is 80.70%. Comparing base (6fd4b25) to head (eb4de19).
Report is 1 commits behind head on release/v0.19.0.

Files with missing lines	Patch %	Lines
src/dist/scaled.rs	18.33%	49 Missing ⚠️
src/data/mod.rs	83.00%	43 Missing ⚠️
src/dist/vonmises.rs	0.00%	33 Missing ⚠️
src/dist/crp.rs	0.00%	9 Missing ⚠️
src/dist/shifted.rs	0.00%	9 Missing ⚠️
src/traits.rs	0.00%	8 Missing ⚠️

Additional details and impacted files

@@                 Coverage Diff                 @@
##           release/v0.19.0      #33      +/-   ##
===================================================
- Coverage            81.05%   80.70%   -0.36%     
===================================================
  Files                   98       98              
  Lines                19711    20081     +370     
  Branches             19711    20081     +370     
===================================================
+ Hits                 15977    16206     +229     
- Misses                3619     3760     +141     
  Partials               115      115              

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[schmidmt]

This all seems reasonable. I like moving to named parameters too.

[schmidmt]

I think in every case the parameters should be sized.

[cscherrer]

Ok I changed it to

pub trait Parameterized: Sized {
    type Parameters;

    fn emit_params(&self) -> Self::Parameters;

    fn from_params(params: Self::Parameters) -> Self;

    fn map_params(
        &self,
        f: impl Fn(Self::Parameters) -> Self::Parameters,
    ) -> Self {
        let params = self.emit_params();
        let new_params = f(params);
        Self::from_params(new_params)
    }
}