#'Writes out a set of samples (SpatialPointsDataFrame) into ESRI shapefiles or a GeoJSON file for a selected habitat type. Each point represents a valid sample location that identifies the selected habitat type.
#'
#' @param inPath file path (character) for results of habitat type sampling and probability mapping (same as outPath from function multi_Class_Sampling)
#' @param step step number (numeric)
#' @param className name (character) of habitat type for which samples should be selected
#' @param output_format format (character) of output; whether shp (default) or geojson
#'
#' @return ESRI shapefiles/GeoJSON with name: SamplePoints_step_classname.shp/SamplePoints_step_classname.geojson
#' 1) Point Shape/GeoJSON represents pixel that belong to selected habitat type and can be used as reference for further model building.
#' ESRI shapefiles have the same CRS as the input raster. GeoJSON files are in the standard CRS of GeoJSON (EPSG:4326).