remove Value type requirement from SampledIntegralProblem

[IlianPihlajamaa]

I found a way to make this Val type unnecessary. This makes the code simpler, type stable, and more performant for small problems.

[codecov[bot]]

Codecov Report

Merging #498 (819ec92) into master (8d293bf) will decrease coverage by 5.52%. The diff coverage is 100.00%.

:exclamation: Current head 819ec92 differs from pull request most recent head d70980e. Consider uploading reports for the commit d70980e to get more accurate results

@@            Coverage Diff             @@
##           master     #498      +/-   ##
==========================================
- Coverage   57.65%   52.14%   -5.52%     
==========================================
  Files          50       50              
  Lines        3710     3709       -1     
==========================================
- Hits         2139     1934     -205     
- Misses       1571     1775     +204     

Files Changed	Coverage Δ
src/problems/basic_problems.jl	89.47% <100.00%> (ø)

... and 17 files with indirect coverage changes

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[IlianPihlajamaa]

How do I make sure the format check is successful?

[lxvm]

How do I make sure the format check is successful?

See this https://docs.sciml.ai/SciMLStyle/stable/#JuliaFormatter

[ChrisRackauckas]

I'll handle that later