Issue 6171 Make MAX_COLLAPSE_DISTANCE configurable in the lua profile

[kaligrafy]

feat: Add configurable max_collapse_distance parameter to Lua profiles
Implements configurable max_collapse_distance parameter to address issue #6171.
This allows precise control over turn instruction collapsing in guidance,
particularly important for pedestrian routing where short crossings need
to be preserved for safety analysis.

Changes:

• Add max_collapse_distance property to ProfileProperties with getter/setter
• Expose parameter to Lua scripting environment for profile configuration
• Add GetMaxCollapseDistance() method to DataFacade interface
• Replace hardcoded MAX_COLLAPSE_DISTANCE constant with thread-local variable
• Update guidance collapse functions to use configurable parameter
• Add documentation and example profile demonstrating usage

The parameter defaults to 30.0 meters (preserving existing behavior) but can
now be customized in Lua profiles:

function setup()
  return {
    properties = {
      max_collapse_distance = 10.0,  -- Custom value in meters
    },
  }
end

This enables sepcific usages who requires precise
pedestrian routing instructions by preventing short road crossings from
being collapsed into longer segments.

#6171