Add Warning When Current PBF File Is Smaller Than Last Months

[pnoll1]

-rw-r--r-- 1 pat pat 73M May 22 08:29 us_ar_alpha.osm.pbf -rw-r--r-- 1 pat pat 59M Jun 21 09:17 us_ar.osm.pbf

A smaller file typically indicates that OpenAddress data had a regression and has fewer addresses than before. OSM data typically grows so files should get bigger each month.

Adding a check after pbf is built to compare with last months file in osmand_osm/osm folder would be a good start and easy to implement. Add a warning to the log flagging that the file is likely worse than last months.