fix: use a single instance of mc ref tracker for all parts of the node

[Rexagon]

We were using a couple of unrelated trackers which caused GC to delete states loaded from the storage despite having alive handles acquired by state applier.

Now we use a single instance of this tracker provided by ShardStateStorage::min_ref_mc_state.

[codecov]

Codecov Report

Attention: Patch coverage is 72.09302% with 12 lines in your changes missing coverage. Please review.

Project coverage is 42.96%. Comparing base (352ec12) to head (4653814).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
block-util/src/state/shard_state_stuff.rs	40.00%	6 Missing ⚠️
core/src/block_strider/starter/cold_boot.rs	0.00%	4 Missing ⚠️
collator/src/test_utils.rs	83.33%	0 Missing and 1 partial ⚠️
core/src/block_strider/state_applier.rs	80.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #568      +/-   ##
==========================================
+ Coverage   42.93%   42.96%   +0.03%     
==========================================
  Files         276      276              
  Lines       51033    51019      -14     
  Branches    51033    51019      -14     
==========================================
+ Hits        21910    21922      +12     
+ Misses      28010    27985      -25     
+ Partials     1113     1112       -1     

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