L2ProjectionInverseDiscretizationConnection should allow modal output

[inducer]

This could avoid the forced (and possibly un-needed) modal-to-nodal conversion at the end of the connection:

meshmode/meshmode/discretization/connection/projection.py

Lines 219 to 229 in cdcc7f5

	return DOFArray(
	actx,
	data=tuple(
	actx.einsum("ij,ej->ei",
	vandermonde_matrix(grp),
	c_i,
	arg_names=("vdm", "coeffs"),
	tagged=(FirstAxisIsElementsTag(),))
	for grp, c_i in zip(self.to_discr.groups, coefficients)
	)
	)

I think this is easy to do since it receives a connection as input. It just needs to check whether the output side of the connection is modal, and if so, skip the extra conversion to nodal.

I noticed this while reviewing #192.

cc @alexfikl @thomasgibson