Feature: IndexedMicrostructure (Definition of individual macroscopic microstructure-phases)

Extended current implementation to 'GlobalMicrostructure'-python classes that feature a macroscopic indicator function determining individual macroscopic microstructure-phases. Each phase can be one of three options:

1. Read effective quantities from ParameterSet (constant microstructure phase)
2. Compute micro-problem once to obtain the effective quantities (constant microstructure phase)
3. Compute micro-problem on each macroscopic quadrature point (macroscopically varying microstructure)

Further additions:

• New/Updated experiments
• macro-problem-testsuite
• microstructure-testsuite