Add lost_part_count column to system.replicas

[serxa]

Changelog category (leave one):

• New Feature

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):

Added a lost_part_count column to the system.replicas table. The column value shows the total number of lost parts in the corresponding table. Value is stored in zookeeper and can be used instead of not persistent ReplicatedDataLoss profile event for monitoring.

Documentation entry for user-facing changes

• Documentation is written (mandatory for new features)

Fixes #47946

[tavplubix]

It would be great to have a test. You can simply modify 01165_lost_part_empty_partition or 02369_lost_part_intersecting_merges

[serxa]

Stateless tests flaky check (asan) — fail: 6

01165_lost_part_empty_partition - timeouts (>60sec) - it is strange because normally it is done in few seconds
02221_system_zookeeper_unrestricted - timeouts - the same problem, normally it is fast