Add MLT tile type
Add tile type for maplibre vector tiles.
https://github.com/onthegomap/planetiler/pull/1355#discussion_r2418257063
Now that MLT will be publicized under https://github.com/maplibre/maplibre.github.io/issues/490#issuecomment-3593232046 I think we should move forward on this
There is some ambiguity regarding future versions of MLT. In contrast, doesn't seem to be ambiguity about MVT 0x01 or future versions of it.
We have one byte in the TileType field to play with. Instead of assigning MLT v1 to 0x06 maybe we should just start at 0x10 and future versions are 0x11 0x12 etc? That makes the sequence of tile types a bit cleaner but of course this is all quite trivial.