Missing CRS on some outputs

Example on get_soil_awc:

sf <- sf::read_sf(
  system.file("extdata/study_area/test.shp", package = "RADIS")
)
# Info & Sols source (90 m raster)
awc_infosols <- get_soil_awc(sf = sf, source = "Info&Sols",
                             overlay_mode = "extent",
                             output_format = "raster")
class      : RasterLayer 
dimensions : 2, 3, 6  (nrow, ncol, ncell)
resolution : 59.99837, 44.99818  (x, y)
extent     : 770292.8, 770472.8, 6283413, 6283503  (xmin, xmax, ymin, ymax)
crs        : NA 
source     : memory
names      : layer 
values     : 67.75197, 95.77362  (min, max)

crs is NA... and it's problematic:

library(tmap)
tm_basemap("OpenStreetMap.France") + tm_shape(awc_infosols) + tm_raster()
Error in `if (isproj) ...`:
! missing value where TRUE/FALSE needed

Possible issues:

• Soil AWC API is not sending CRS
• get_soil_awc on Info&Sols doesn't get CRS on raster stack reading (can be solved by #44 (closed) if using terra?)

However, spatial_combination is supposed to return same CRS as the sf input mask. So it should at least warn if there is no CRS in the data input.