[TBBAS-1459] Python bindings: MultiReader

[Yarikk26]

Type of change

• [x] New feature (non-breaking change which adds functionality)

Checklist:

• [x] Pull request title reflects its content
• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [ ] Any dependent changes have been merged and published in downstream modules

Description:

• MultiReader and TimeMultiReader added to Python bindings
• Tests updated
• MockSignal updated