Generalize the verification function `check_values()`.

The function check_values() in minterpy.core.verification is generalized to accept either a scalar or a NumPy array. The optional arguments have been extended:

• nan: Allow NaN value if True (default False)
• inf: Allow inf value if True (default False)
• negative: Allow negative value if True (default True)
• zero: Allow zero value if True (default True)

This MR should fix Issue #131 (closed).

Additional changes:

• The usage of the function check_values() in the code base is updated.
• The test suite of MultiIndexSet is updated to include testing the behavior where a given exponents array is negative.
• The tests for verification functions are updated to include testing the new function.