🐛 Fix GoingToCamp KeyError when listing campgrounds

[justin-outdoorithm]

Summary

Fixes #377 - GoingToCamp provider raises KeyError when calling find_campgrounds() for any recreation area.

Root Cause

The CAMP_DETAILS API returns regional map data where all entries have resourceLocationId=None, causing the campground_details dictionary to only contain {None: <last_entry>}. When _process_facilities_responses tries to look up the actual facility's resource_location_id, it raises a KeyError.

The Fix

The LIST_CAMPGROUNDS API response already contains rootMapId for each facility. This fix uses that value directly instead of the broken CAMP_DETAILS lookup.

Changes:

• Add root_map_id field to ResourceLocation class in gtc_api_responses.py
• Capture rootMapId from LIST_CAMPGROUNDS in _filter_facilities_responses()
• Use facility.root_map_id directly in _process_facilities_responses()
• Remove unused CAMP_DETAILS API call and campground_details dictionary

Testing

Tested locally against all affected recreation areas:

• Washington State Parks (rec_area_id=3) - 78 campgrounds ✓
• Wisconsin State Parks (rec_area_id=7) - 50 campgrounds ✓
• BC Parks (rec_area_id=1) - 110 campgrounds ✓
• Parks Canada (rec_area_id=2) - 76 campgrounds ✓

Before (crashes)

provider = GoingToCamp()
campgrounds = provider.find_campgrounds(rec_area_id=[3])
# KeyError: -2147483647

After (works)

provider = GoingToCamp()
campgrounds = provider.find_campgrounds(rec_area_id=[3])
# Returns 78 campgrounds for Washington State Parks