Add functionality to write surfaces to the trends folder in RMS

[tnatt]

From RMS v.14.2 the rmsapi supports writing surfaces to the trends folder.

This enables the removal of the workaround here

xtgeo/src/xtgeo/surface/_regsurf_roxapi.py

Lines 192 to 212 in 934e94c

	elif stype == "trends":
	if name not in proj.trends.surfaces:
	logger.info("Name %s is not present in trends", name)
	raise ValueError(
	f"Name {name} is not within Trends (it must exist in advance!)"
	)
	# here a workound; trends.surfaces are read-only in Roxar API, but is seems
	# that load() in RMS is an (undocumented?) workaround...
	try:
	import roxar
	except ImportError as err:
	raise ImportError(
	"roxar not available, this functionality is not available"
	) from err
	roxsurf = proj.trends.surfaces[name]
	with tempfile.TemporaryDirectory() as tmpdir:
	logger.info("Made a tmp folder: %s", tmpdir)
	self.to_file(os.path.join(tmpdir, "gxx.gri"), fformat="irap_binary")
	roxsurf.load(os.path.join(tmpdir, "gxx.gri"), roxar.FileFormat.ROXAR_BINARY)