arc: raise a clear error for a zero or non-finite axis or angle - #2127

pdf.arc(10, 10, 0, 0, 90) raised ZeroDivisionError: float division by zero, and a NaN axis or angle raised ValueError: cannot convert float NaN to integer. solid_arc() is built on arc() and failed the same way.

arc() now raises ValueError: Arc axes must be non-zero finite numbers: ... for a zero, NaN or infinite a/b, and ValueError: Arc angles must be finite numbers: ... for a NaN or infinite start_angle, end_angle or inclination. Negative axes are still accepted as before.

• A unit test is covering the code added / modified by this PR
• A mention of the change is present in CHANGELOG.md
• This PR is ready to be merged