edr_r: Run ED two-stream radiative transfer model
In ashiklom/edr-da: ED2 RTM testing functions

Wrapper around [sw_two_stream] that also calls PROSPECT 5 (see [PEcAnRTM::prospect()]) to generate the leaf reflectance and transmittance spectra, [hapke_soil()] to generate the soil spectrum given 'soil_moisture', and a "flat" incident solar spectra for direct and diffuse light based on 'direct_sky_frac'.

edr_r(
  pft,
  lai,
  wai,
  cai,
  N,
  Cab,
  Car,
  Cw,
  Cm,
  orient_factor,
  clumping_factor,
  soil_moisture,
  direct_sky_frac,
  czen,
  wood_reflect = matrix(rep(wood_spec, length(pft)), 2101),
  wavelengths = seq(400, 2500),
  ssa_type = "sellers"
)

`pft`	PFT identities of each cohort, as integer (ncoh). Shortest to tallest.
`lai`	Leaf area index of each cohort (ncoh). Shorest to tallest.
`wai`	Wood area index of each cohort (ncoh). Shorest to tallest.
`cai`	Crown area of each cohort (ncoh). Shorest to tallest.
`N`	PROSPECT 5 effective number of leaf mesophyll layers (>1; npft)
`Cab`	PROSPECT 5 leaf chlorophyll content (ug cm-2; npft)
`Car`	PROSPECT 5 leaf carotenoid content (ug cm-2; npft)
`Cw`	PROSPECT 5 leaf water content (g cm-2; npft)
`Cm`	PROSPECT 5 leaf dry matter content (g cm-2; npft)
`orient_factor`	Orient factor (npft)
`clumping_factor`	Clumping factor (npft)
`soil_moisture`	Soil moisture index (0-1; 0 = completely dry, 1 = completely wet)
`direct_sky_frac`	Fraction of incident solar radiation that is direct (0-1; 0 = all diffuse radiation)
`czen`	Cosine of angle of incidence ('cosaio')
`wood_reflect`	Wood reflectance spectrum. Default [wood_spectrum()]
`wavelengths`	Numeric vector of wavelengths to use, in nm (nwl). Default is 400:2500.