t.rast.ndvi: Allow user to specify nir and red band names

[jonas-eberle]

Currently, t.rast.ndvi tries to find out the band names for nir and red automatically:

openeo-addons/t.rast.ndvi/t.rast.ndvi.py

Lines 106 to 125 in c78a130

	red_band = None
	nir_band = None
	if sensor_abbr is not None:
	if sensor_abbr == "L5":
	red_band = "L5_3"
	nir_band = "L5_4"
	elif sensor_abbr == "L7":
	red_band = "L7_3"
	nir_band = "L7_4"
	elif sensor_abbr == "L8":
	red_band = "L8_4"
	nir_band = "L8_5"
	elif sensor_abbr == "S2":
	red_band = "S2_4"
	nir_band = "S2_8"
	if red_band is None:
	grass.warning("Assuming 'red' and 'nir as band names in %s" % _input)
	red_band = "red"
	nir_band = "nir"

As we have now flexible band names in GRASS GIS available and to support the ndvi process of openEO, it would be good to have the band names as input parameters. This could then be passed directly from the openEO process graph:
https://github.com/Open-EO/openeo-grassgis-driver/blob/81595797ab5d1df1953a99eb61c2531375ab7146/src/openeo_grass_gis_driver/actinia_processing/ndvi_process.py#L96-L107

[metzm]

Fixed in d9f5e1a on 28 Nov 2021

[mmacata]

@metzm so this issue can be closed?