Add check for "too close nodes" (<3m) within highways

[Dmitry Olyenyov <dmitry.olyenyov@…>]

This check will be especially useful for converting maps into Navitel's map format.

[Daeron]

No, that's stupid. There are lot's of things that need more accuracy than 3m, eg. buildings right next to a footway etc.

[stoecker]

We already have a close nodes check. And we have checks for nodes near ways and so on. There is no need for an additional check like this. We can change the definitions for some of the checks when it is necessary.

[Dmitry Olyenyov <dmitry.olyenyov@…>]

Can we check that 2 nodes along the way are too close? Only for highways.

[hamish_b@…]

see also #4445

[tordanik]

From personal experience, there are many situations where subsequent nodes within highways are closer than 3 m. This makes a lot of sense for winding steps, bends in paths and so on. I expect node placement at an accuracy below 3 m to be pretty commonplace in those parts of the world that are already mapped at a high level of detail. In my opinion, that's a good thing and not something the validator should complain about.