Feature Request for Gdal2Tiles: Add How many tiles were actually created

[asafMasa]

Expected behavior and actual behavior.

Description: For our use case we need to know how many tiles were created for a certain gdal2tiles operation

Expected behavior: Gdal2Tiles will specify how many tiles were created when the operation ends. :grinning:

Actual behavior: Gdal2Tiles don't specify, and recursive check on S3 / FS sucks :frowning_face:

Steps to reproduce the problem.

run gdal2tiles