Update default params and param validations of methods in Tissue Library

[RecurvedBow]

Please describe your refactor. Due to the test TestCoreAssumptions.test_volume_fractions_sum_to_less_or_equal_one(), all function parameters have to define a default value. This does not always make sense however for the method constant and the method to implement in #283. The test should be replaced with a test for every Tissue library method each, or specialized test cases have to be implemented for these two cases.

In addition to that, some default arguments of methods in the Tissue library accept None. This should also be refactored since in these cases, the function args are replaced with alternative constant values. Please use these constant values directly as default args for these parameters.

Finally, add asserts for the function arguments, so that setting params as None is not valid, that the args are of the correct type, and if the args should only be in a certain range (such as blood volume fraction), add the corresponding assert too.

All changes, including all added validations, have to be tested.