Add rasterize() validation-guard test coverage (#3383)

Cover the input-validation guards in rasterize() that had no error-path
tests: non-representable integer/bool fill, burn values above the float64
safe-integer range, non-finite burn values into integer/bool dtypes (with
the merge='count' exemption), and non-finite geometry coordinates dropped
with a warning. Test-only; all guards run on the CPU path pre-dispatch.

Also record the pass in the sweep-test-coverage state CSV.

Author: brendancol