UM transects are plotted upside down

[daflack]

Describe the bug

UM transects appear to be plotted upside when used in ensemble mode. This bug is particularly clear for things like PV (e.g. below).

How to reproduce

Steps to reproduce the behaviour:

1. Select transect with UM ensemble data.

Expected behaviour

Should be plotted the correct way round.

[daflack]

CSET/src/CSET/operators/misc.py

Lines 322 to 335 in 48f208b

	def is_increasing(sequence: list) -> bool:
	"""Determine the direction of an ordered sequence.
	Returns "increasing" or "decreasing" depending on whether the sequence
	is going up or down. The sequence should already be monotonic, with no
	duplicate values. An iris DimCoord's points fulfills this criteria.
	"""
	return sequence[0] < sequence[1]
	# Figure out if we are comparing between UM and LFRic; flip array if so.
	base_lat_direction = is_increasing(base.coord(base_lat_name).points)
	other_lat_direction = is_increasing(other.coord(other_lat_name).points)
	if base_lat_direction != other_lat_direction:
	other.data = np.flip(other.data, other.coord(other_lat_name).cube_dims(other))

could be useful