Add an option to extend zooms if still dropping, but with a limit

[e-n-f]

There are two changes here:

1. Add the --extend-zooms-if-still-dropping-maximum option, which allows the zoom range to be extended if features are still being dropped at maxzoom, but with a limit on the number of zoom levels that may be added
2. Add the --overzoom option to tile-join, which gives it the long-requested ability to join tilesets with different maxzooms, overzooming tiles from the lower-maxzoom tilesets to extend their zoom range to match the higher-maxzoom tilesets.

Fixes mapbox/tippecanoe#693

[ibesora]

Looked at this with @e-n-f and everything looks good.
As a small thing to tackle in the future, it'd be great if all the triplicated code that happens due to supporting mbtiles, pmtiles and directories, could live on three different sub classes implementing a common interface

[Sergeyev]

Hello!

A strange bug, appears at geojson with 38M objects. At smaller ones (about 1M) - did not appear.

Compiled from https://github.com/felt/tippecanoe#overzooming

At levels 1..14, "Geometry" is added to the "properties" of objects, them become heavy, and with --drop-densest-as-needed application leaves only a few objects per tile.

(screenshot from DBeaver, tile from 13 level)

Here is a part of the original GeoJSON with the same object "2cc5f9f3-a507-4863-9922-466bbb8fba95", there are no "Geometry" inside "properties":

{"type": "Feature", "properties": {"style": "osm_style", "ID": 7963555, "GlobalID": "2cc5f9f3-a507-4863-9922-466bbb8fba95", "clusterID": null, "clusterID2": null, "Region": null, "Municipalitet": null, "Street": null, "HouseNumber": null, "Street2": null, "HouseNumber2": null, "RegionCode": "63", "buildingType": "ИЖС", "flatsCount": null, "peopleCount": null, "transportAccessibility": 0, "AutoAccessibility": null, "foodOrgs": 0, "educationOrgs": {"category": "Школы", "dist": 2962.2548297919125, "orgID": 1130, "orgName": "Гармония, МБОУ, школа №41 с углубленным изучением отдельных предметов"}, "sources": {"regional": 0, "lands": 1, "fias": 0, "oks": 1, "reformagkh": 0, "uiks": 0, "msml": 0, "osm": 1}, "fiasAddress": null, "osmAddress": null, "uiksAddress": null, "landsAddress": null, "tkoAddress": null, "sksAddress": null, "reformagkhAddress": null, "oldAPAddress": null, "msmlAddress": null, "oksAddress": null}, "geometry": {"type": "Polygon", "coordinates": [[[50.1208417, 53.239470499999996], [50.1209698, 53.2396022], [50.1211221, 53.2395491], [50.120993899999995, 53.2394174], [50.1208417, 53.239470499999996]]]}, "centroid": null, "_id": {"$oid": "670bd04544319c02d2a83f0e"}}

At levels 15..17 - everything is fine.
In old version - everything is fine.