wic/engine: warn about old host debugfs for standalone directory copy

wic/engine: warn about old host debugfs for standalone directory copy

When wic is used in standalone mode, it relies on host tools such as
debugfs. For directory host->image copies into ext* partitions, wic
uses scripted debugfs "-f" input with multiple mkdir/write commands.

Older host debugfs versions (< 1.46.5) may behave unreliably in this
mode and can silently miss files. This does not affect builds using
debugfs from OE where the version is known to be sufficiently new.

Add a debugfs version check and emit a warning when an older host
debugfs is detected. The warning is shown once per run and does not
alter execution.

Changes in v2:
- adjust the last working debugfs version to 1.46.5

Signed-off-by: Daniel Dragomir <daniel.dragomir@windriver.com>
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>