Fixing the respiratory epithelial cell hierarchy

[dosumis]

• respiratory epithelial cell is defined as an endo-epithelial cell but 'epithelial cell' is used to define many subclasses. #2379

• Make respiratory epithelial cells part of epithelia, not the larger regions that contain epithelia #2376
  Example: respiratory epithelial cell is defined a part of the respiratory tract, rather than part of the respiratory tract epithelium

• Make the submucosal glands of the respiratory tract part of the respiratory epithelium (they are continuous with it). uberon#3282

• Rationale: the submucosal glands of the respiratory tract are continuous with (part of) the respiratory tract epithelium, but this is not reflected in Uberon - this results in disjointed hierarchy that splits of submucosal gland cell types from similar cells in the rest of the respiratory epithelium. Note - It is OK to have some subdivision of the respiratory epithelium that divides these, but we need a general term under which the general cell type exist.

• Delete asserted classifications of respiratory epithelial cell types by region where autoclassification is possible. #2378