Added test for PCA and improved `pca_transformation`

See merge request !24

An example 'principal_component_analysis' was added to specifically test this functionality. It uses the analytical model.
Fixed two if-calls in `pca_transformation` to match older code and the content of the function.

Created an example specifically to test this feature

See merge request !23

Update bvr in branch

See merge request !22

Decoupled MCMC from BayesInference and improved performance

See merge request !21

# Conflicts:
#   src/bayesvalidrox/surrogate_models/engine.py

MCMC does not receive the whole BayesInf object anymore, performance of inference now should be back up to speed with MCMC. In future perhaps rework so that MCMC is a child class of BayesInf?

Tests for BayesInf and general cleanup

See merge request !20

# Conflicts:
#   src/bayesvalidrox/bayes_inference/bayes_inference.py
#   src/bayesvalidrox/bayes_inference/bayes_model_comparison.py
#   src/bayesvalidrox/bayes_inference/mcmc.py

This reverts commit acf483a1

Split the model comparison to be callable in functions for bayes factors, model weights and justifiability analysis and renamed the overall function

BMC only runs the BME part of BayesInf, split JA into its own function, removed redundant function in MCMC, added to function diagrams

More test for BayesInf, starting tests for MCMC

Some simple fixes for various test, start on testing BayesInf, output directory as changeable parameter in BayesInf

UMBridge examples cleaned and pylink 'single-valued' removed