Consolidate foot-/cycle-/bridleways into designated paths

[hlfan]

The path road class with designated entries for access_restrictions is more modular than foot-, cycle- and bridleways, these three road classes were originally supposed to be replaced by paths, but the map-making community preferred to keep these as shortcuts. This, however, increased the complexity for OSM data consumers.
While Overture already gets rid of the possibility of possibly only implied access restrictions, the unnecessary distinction between designated paths and foot-/cycle-/bridleways remains.

I'm proposing to combine these redundant road classes into path, as the access restrictions already cover the differences.