Improvement of the vector + linop axiom tests

[Simkern]

Some improvements of the axiomatic tests.

• Added book-keeping such that, if one of the axiom tests fails, the tester outputs the trial as well as the axiom that failed, together with the error_norm to facilitate debugging.
• Added a similar axiomatic test framework for the linops testing additivitiy, homogeneity, origin preservation and, optionally, adjoint consistency. These wrappers can then also be applied by users to their own implementations for sanity checks. For the operator homogeneity that will be tested in parallel with a global operator, I choose to use a deterministic non-trivial scaling factor for the test to avoid awkward communication while retaining global consistency for operator test in a parallel environment.

[codecov]

Codecov Report

❌ Patch coverage is 76.11940% with 128 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/AbstractTypes/AbstractVectors.f90	57.44%	80 Missing ⚠️
src/AbstractTypes/AbstractLinops.f90	82.85%	48 Missing ⚠️

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