Adjust subsolver module to components interface

[timmens]

This PR updates the solve_subproblem.py module and subsolver code.

• Add starting parameters to subsolvers (x_candidate)
• Dynamically switch between cube and sphere subsolver depending on trustregion shape
• Use get_component to get sphere and cube subsolver functions
• Pass bounds of -1 and 1 to subsolvers in tranquilo
• Update documentation
• Update living documentation

[codecov]

Codecov Report

Merging #448 (a04efd6) into main (0d02ac9) will increase coverage by 0.05%.
The diff coverage is 100.00%.

❗ Current head a04efd6 differs from pull request most recent head 47d856f. Consider uploading reports for the commit 47d856f to get more accurate results

@@            Coverage Diff             @@
##             main     #448      +/-   ##
==========================================
+ Coverage   93.19%   93.25%   +0.05%     
==========================================
  Files         247      247              
  Lines       18029    17988      -41     
==========================================
- Hits        16803    16775      -28     
+ Misses       1226     1213      -13     

Impacted Files	Coverage Δ
src/estimagic/optimization/subsolvers/bntr.py	86.32% <ø> (-0.06%)	⬇️
...imagic/optimization/tranquilo/process_arguments.py	100.00% <ø> (ø)
src/estimagic/optimization/pounders_auxiliary.py	97.32% <100.00%> (ø)
src/estimagic/optimization/subsolvers/gqtpar.py	90.54% <100.00%> (-0.07%)	⬇️
...timagic/optimization/tranquilo/solve_subproblem.py	100.00% <100.00%> (+13.25%)	⬆️
...magic/optimization/tranquilo/wrapped_subsolvers.py	20.51% <100.00%> (+1.00%)	⬆️
tests/optimization/subsolvers/test_bntr_fast.py	100.00% <100.00%> (ø)
tests/optimization/test_quadratic_subsolvers.py	100.00% <100.00%> (ø)
tests/optimization/tranquilo/test_rho_noise.py	100.00% <100.00%> (ø)
...ts/optimization/tranquilo/test_solve_subproblem.py	100.00% <100.00%> (ø)

... and 3 files with indirect coverage changes

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.