samples/damon: introduce a skeleton of a smaple DAMON module for proactive reclamation

samples/damon: introduce a skeleton of a smaple DAMON module for proactive reclamation

DAMON is not only for monitoring of access patterns, but also for
access-aware system operations.  For the system operations, DAMON provides
a feature called DAMOS (Data Access Monitoring-based Operation Schemes).
There is no sample API usage of DAMOS, though.  Copy the working set size
estimation sample modules with changed names of the module and symbols, to
use it as a skeleton for a sample module showing the DAMOS API usage.  The
following commit will make it proactively reclaim cold memory of the given
process, using DAMOS.

Link: https://lkml.kernel.org/r/20241210215030.85675-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>