[SEDONA-754] feat: make rasterization orientation-agnostic by supporting positive scaleY

[prantogg]

Did you read the Contributor Guide?

• Yes, I have read the Contributor Rules and Contributor Development Guide

Is this PR related to a ticket?

• Yes, and the PR name follows the format [SEDONA-XXX] my subject.

What changes were proposed in this PR?

Rasterization assumes top-down orientation (negative scaleY) and throws an error for positive scaleY values. Bottom-up rasters (positive scaleY) are common in formats like BMP and certain GeoTIFF configurations.

This PR makes rasterization orientation-agnostic by:

• Detecting bottom-up rasters (positive scaleY) and flipping the grid space internally during rasterization
• Flipping the result back after rasterization so the output matches the requested orientation
• Adding flipVerticallyGridSpace helper to RasterUtils
• Removing the scaleY > 0 restriction from RS_AsRaster documentation

How was this patch tested?

• Added tests for positive scaleY rasterization
• Passes all existing rasterization tests (RS_ZonalStats, RS_SetValues, RS_Clip)

Did this PR include necessary documentation updates?

• Yes, removed the restriction note about positive scaleY from the RS_AsRaster documentation.