Current data partition block size and growfs related issues

[kirillkovalenko]

Data partition seems to have 1k block size which is sub-optimal, because

1. when data partition gets resized automatically via systemd-growfs it
   a. takes very long time, which is confusing, it appears as if the boot process has stuck (users complain about it on discord)
   b. makes VM disk thin provisioning impossible, e.g. for a 3TB thin provisioned image file, it gets 670GB immediately allocated when growfs has finished.

2. manual, on the fly resize of the image file and data partition is problematic because data partition is created with 1k block size could not be easily resized to a big disk using resize2fs. the problem was discussed on e2fsprogs github and a suggested solution is that images should be created using 4k block size from the very beginning.