Chloe Whicker

Results 3 issues of Chloe Whicker

- Adds support for hourly ERA5 forcing (ELMERA5) and the 6 hourly ERA5 forcing (ERA56HR) from 1979-2021. - Adds tests for the new compsets. [BFB]

Land

Removes incorrectly placed line in elm_instMod.F90 for `use_extrasnowlayers = .true.` [BFB]

Land
BFB

Introduced new diagnostic Surface Mass Balance fields, they are calculated as if there is a coupled land ice component but are only diagnostic - it does not modify the energy/water...

Land
BFB