Update CMake export config

[dweindl]

• We don't need to find SuiteSparse - sundials takes care of that
• Fixes some issues when consuming the amici-exported CMake config
• Set CMAKE_PREFIX_PATH when configuring models
• Install system-wide libsuitesparse-dev to make sure it doesn't interfere with our vendored version

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.78%. Comparing base (4973321) to head (91f0a8e).
Report is 1 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2540      +/-   ##
===========================================
+ Coverage    77.75%   77.78%   +0.02%     
===========================================
  Files          325      325              
  Lines        21058    21058              
  Branches      1473     1473              
===========================================
+ Hits         16373    16379       +6     
+ Misses        4658     4652       -6     
  Partials        27       27              

Flag	Coverage Δ
cpp	73.49% <ø> (+0.02%)	⬆️
cpp_python	34.05% <ø> (ø)
petab	37.05% <ø> (ø)
python	72.33% <ø> (+0.03%)	⬆️

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see 4 files with indirect coverage changes