CLAHE Transform

Is your feature request related to a problem? Please describe.
I was wondering if I could attempt to implement a CLAHE transform into the MONAI library or if one is being worked. Contrast Limited Adaptive Histogram Equalization is widely used in medical 2D imaging, especially Ophthalmology. While other libraries do have implementations and is possible to do via Lambda transformation, perhaps a tried and tested transform could be developed for MONAI

Describe the solution you'd like
I imagine it would fall under an Intensity Transform and follow the pattern set there. Both Vanilla and Dictionary

Describe alternatives you've considered
It is entirely possible to do this as a lambda transform but with more and more people utilizing MONAI, it would be a gentler introduction for a common transform.

Additional context
My First issue/feature request--I am actually planning to do the coding, but have no contributed much to open source, so probably lots of questions (I did try to RTFM)

Start by reading MONAI's existing Intensity Transform implementations and the patterns for Vanilla and Dictionary transforms. The issue does not name specific files or tests, so locate those entry points first. Done means a CLAHE transform is available in both requested forms and is covered for medical 2D imaging use cases.