Store structure matrices and vectors with names as dictionaries

[ArneBouillon]

• Add structure vectors along with structure matrices
• Store structure matrices and vectors in dictionaries, so that they can be named in case a specific matrix/vector is needed
• I'm not entirely convinced by my solution of passing encoder_kwargs to Emulator, but I don't really have a better idea. Let me know if you do!

Misc:

• build_models! now only accepts the expected keyword arguments, throws errors if unknown kwargs are passed.

[odunbar]

Hey! Thanks for the progress - this looks great. I have left a few small comments.

• I do notice that the buildkite fails, Presumably we need to update a few of the examples. The specific failures it hits are on the Lorenz and the Regression examples - failing due to
  • (1) Please provide a structure matrix
  • (2) no method matching build_models!(::GaussianProcess{SKLJL, Float64, Vector{Float64}}, ::PairedDataContainer{Float64}, ::Dict{Symbol, Union{UniformScaling, AbstractMatrix}}, ::Dict{Symbol, Union{UniformScaling, AbstractMatrix}}; input_structure_matrix::Diagonal{Float64, Vector{Float64}}, output_structure_matrix::Matrix{Float64})

[codecov]

Codecov Report

❌ Patch coverage is 91.57895% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.98%. Comparing base (a318edb) to head (9abb476).
⚠️ Report is 16 commits behind head on main.

Files with missing lines	Patch %	Lines
src/Utilities.jl	90.90%	4 Missing ⚠️
src/GaussianProcess.jl	86.66%	2 Missing ⚠️
src/ScalarRandomFeature.jl	80.00%	1 Missing ⚠️
src/VectorRandomFeature.jl	85.71%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #373      +/-   ##
==========================================
+ Coverage   90.80%   90.98%   +0.18%     
==========================================
  Files          10       10              
  Lines        1577     1609      +32     
==========================================
+ Hits         1432     1464      +32     
  Misses        145      145              

☔ 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.

[odunbar]

If you could resolve the last codecov requests, this looks good to me! Thanks!