Finding Nearby Features loads every generated chunk in radius

[Developer Report]

The code that finds the nearest feature in a radius around a position, used by locate, dolphins and treasure maps, is using the wrong method to look up chunks, resulting in every chunk that has been generated to be loaded by the command, crashing servers.

The code never did this pre 1.13, so clearly this was a bug.

I traced it down that the wrong getChunk method was used, which forwards to the correct one with the load boolean always set to true

Switching it like so still finds structures correctly:

private StructureStart a(GeneratorAccess generatoraccess, ChunkGenerator<? extends GeneratorSettings> chunkgenerator, SeededRandom seededrandom, long i) {
        if (!chunkgenerator.getWorldChunkManager().a(this)) {
            return StructureGenerator.a;
        } else {
            Long2ObjectMap long2objectmap = chunkgenerator.getStructureStartCache(this);
            StructureStart structurestart = (StructureStart) long2objectmap.get(i);

            if (structurestart != null) {
                return structurestart;
            } else {
                ChunkCoordIntPair chunkcoordintpair = new ChunkCoordIntPair(i);
                IChunkAccess ichunkaccess = generatoraccess.getChunkProvider().getChunkAt(chunkcoordintpair.x, chunkcoordintpair.z, false, false); // Paper - don't load chunks

                if (ichunkaccess != null) {
                    structurestart = ichunkaccess.a(this.a());
                    if (structurestart != null) {
                        long2objectmap.put(i, structurestart);
                        return structurestart;
                    }
                }

                if (this.a(chunkgenerator, seededrandom, chunkcoordintpair.x, chunkcoordintpair.z)) {
                    StructureStart structurestart1 = this.a(generatoraccess, chunkgenerator, seededrandom, chunkcoordintpair.x, chunkcoordintpair.z);

                    structurestart = structurestart1.b() ? structurestart1 : StructureGenerator.a;
                } else {
                    structurestart = StructureGenerator.a;
                }

                if (structurestart.b()) {
                    generatoraccess.getChunkProvider().a(chunkcoordintpair.x, chunkcoordintpair.z, true).a(this.a(), structurestart);
                }

                long2objectmap.put(i, structurestart);
                return structurestart;
            }
        }
    }