cicwi/PyCorrectedEmissionCT: Release version 0.2.3

New release adding the following features and fixing the following bugs:

• On-demand padding for Wavelet regularizer
• Projection intensity rescaling for different angles in base projector
• Support for 3D absorption maps (but not thouroughly tested, yet)
• Data-term residual computation to all solvers
• Some tests to solvers and regularizers
• Automated testing and linting on github workflows
• Support for ASTRA's super-sampling of pixels and voxels
• Implemented scipy's sparse LinearOperator interface for the projectors
• Utility min-log and simple flat-fielding functions for transmission data ### Fixed
• Copy-paste error, and detector data axis order in SART algorithm implementation
• Weights for masks in SART algorithm
• Error in unpreconditioned CP implementation
• Applied linting changes, to improve the readability of the code