Bug/sc 458619/allow negative values on most common approx

[rantolin]

Issue

This PR fixes these two bugs:

1. https://app.shortcut.com/cartoteam/story/458606/error-when-nodata-value-is-assigned-to-0-in-raster-loader
2. https://app.shortcut.com/cartoteam/story/458619/allow-negative-values-on-most-common-approx-counts

Proposed Changes

Changes fix two bugs related to computation of approximate stats:

1. Casting to integer raises OverflowError when sum is infinity. We now catch this error and handle it.
2. We refactored most_common_approx which is now using numpy.histogram to support the computation of approximate most common negative integer values

Pull Request Checklist

• I have tested the changes locally
• I have added tests to cover my changes (if applicable)
• I have updated the documentation (if applicable)

[vdelacruzb]

LGTM