[Disk Manager]: Do not hang on mkfs.ext4 in sync tests

[jkuradobery]

Add -F parameter to the sync tests in order to avoid hanging on the disk reuse.

[jkuradobery]

There is no point in using the -F key. The explaination is the following:
mkfs.ext4 is pretty much mke2fs. And it checks for the file-system being present and asks for input afterwards.
https://github.com/tytso/e2fsprogs/blob/master/misc/util.c#L96
In "right" tests we did not create pseudo-terminal, so mke2fs just creates the filesystem. To avoid affecting "right" tests, we should just change our ssh client implementation by adding the -T parameter. Will abandon this PR and create a new one.
@qkrorlqr @WilyTiger @SvartMetal