Update constraint interface

[timmens]

Update constraints interface according to EEP-02 (changes described here)

• Also adds some tests for pytree handling in derivatives

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[codecov]

Codecov Report

Attention: Patch coverage is 88.94472% with 22 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/optimagic/constraints.py	85.31%	21 Missing ⚠️
...imagic/optimization/create_optimization_problem.py	75.00%	1 Missing ⚠️

Files with missing lines	Coverage Δ
src/estimagic/estimate_ml.py	82.47% <100.00%> (+0.07%)	⬆️
src/estimagic/estimate_msm.py	89.68% <100.00%> (+0.43%)	⬆️
src/optimagic/__init__.py	100.00% <100.00%> (+8.69%)	⬆️
src/optimagic/deprecations.py	100.00% <100.00%> (ø)
src/optimagic/optimization/optimize.py	91.26% <ø> (-0.17%)	⬇️
src/optimagic/parameters/constraint_tools.py	100.00% <100.00%> (ø)
src/optimagic/parameters/process_constraints.py	96.49% <100.00%> (ø)
src/optimagic/shared/process_user_function.py	98.52% <ø> (ø)
...imagic/optimization/create_optimization_problem.py	86.16% <75.00%> (+0.12%)	⬆️
src/optimagic/constraints.py	85.31% <85.31%> (ø)

... and 2 files with indirect coverage changes

[janosg]

Thanks!