On first look, this function seems to work the same as Poisson function that we already support. https://support.microsoft.com/en-us/office/poisson-dist-function-8fe148ff-39a2-46cb-abf3-7772695d9636 https://support.microsoft.com/en-us/office/poisson-function-d81f7294-9d7c-4f75-bc23-80aa8624173a
added r1901371