Bug triangulations

Found a bug when computing the view of an appended triangulation (`SubCellTriangulation` + `BodyFittedTriangulation`).

```
using Gridap
using Gridap.Arrays
using Gridap.Geometry
using GridapEmbedded

D = 2

model = CartesianDiscreteModel((0,1,0,1),(10,10))

geo = disk(0.1,x0=Point(0.5,0.5))
cutgeo = cut(model,geo)

Ω = Triangulation(cutgeo,PHYSICAL_OUT)
Ω_view = view(Ω,[num_cells(Ω)])

glue = get_glue(Ω_view,Val(D))
tface_to_mface_map = glue.tface_to_mface_map

c = array_cache(tface_to_mface_map)
getindex!(c,tface_to_mface_map,1) # crashes

# source of problem
parent_glue = get_glue(Ω_view.parent,Val(D))
ids = Ω_view.cell_to_parent_cell
tface_to_mface_map = lazy_map(Reindex(parent_glue.tface_to_mface_map),ids) # wrong eltype
```