Mas p401 coverage (#404)

* refactor leveled_sst from gen_fsm to gen_statem

* format_status/2 takes State and State Data
but this function is deprecated... put in for backward compatibility

* refactor leveled_cdb from gen_fsm to gen_statem

* disable irrelevant warning ignorer

* Remove unnecessary code paths

Only support messages, especially info messages, where they are possible.

* Mas i1820 offlinedeserialisation cbo (#403)

* Log report GC Info by manifest level

* Hibernate on range query

If Block Index Cache is not full, and we're not yielding

* Spawn to deserialise blocks offline

Hypothesis is that the growth in the heap necessary due to continual term_to_binary calls to deserialise blocks is wasting memory - so do this memory-intensive task in a short-lived process.

* Start with hibernate_after option

* Always build BIC

Testing indicates that the BIC itself is not a primary memory issue - the primary issue is due to a lack of garbage collection and a growing heap.

This change enhances the patch to offline serialisation so that:
- get_sqn & get_kv are standardised to build the BIC, and hibernate when it is built.
- the offline PId is linked to crash this process on failure (as would happen now).

* Standardise spawning for check_block/3

Now deserialise in both parts of the code.

* Only spawn for check_block if cache not full

* Update following review

* Standardise formatting

Make test more reliable.  Show no new compaction after third compaction.

* Update comments

---------

Co-authored-by: Thomas Arts <thomas.arts@quviq.com>

src/leveled_log.erl

@@ -168,6 +168,8 @@
             {info, <<"At level=~w file_count=~w avg_mem=~w file with most memory fn=~s p=~w mem=~w">>},
         pc024 =>
             {info, <<"Grooming compaction picked file with tomb_count=~w">>},
+        pc025 =>
+            {info, <<"At level=~w file_count=~w average words for heap_block_size=~w heap_size=~w recent_size=~w bin_vheap_size=~w">>},
         pm002 =>
             {info, <<"Completed dump of L0 cache to list of l0cache_size=~w">>},
         sst03 =>