Add find_max_value_coords function

[giswqs]

import leafmap

# Example usage:
geotiff_file = "cog.tif"

# Without specifying dst_crs, it will return original x, y
x, y, max_value = leafmap.find_max_value_coords(geotiff_file)
print(f"Original Coordinates: (x: {x}, y: {y}), Maximum Value: {max_value}")

# With dst_crs (e.g., EPSG:4326 for lat/lon)
x, y, max_value = leafmap.find_max_value_coords(geotiff_file, dst_crs="EPSG:4326")
print(f"Reprojected Coordinates: (x: {x}, y: {y}), Maximum Value: {max_value}")