Remove Validator Map Copies

[nisdas]

What type of PR is this?

Feature Improvement

What does this PR do? Why is it needed?

• Reverts back to our original behaviour to have a single map utilized by all shared states. This breaks the invariant that
  all state operations are restricted to the underlying state. However, given that we can handle indexes not in the current registry
  this edge case can be appropriately handled. The assumptions here are that deposit processing and ordering are fixed, so
  all validators will always be included in the same order.

Which issues(s) does this PR fix?

Replaces #8854

Other notes for review

[codecov]

Codecov Report

Merging #8860 (8454a3d) into develop (8dd2915) will decrease coverage by 0.05%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop    #8860      +/-   ##
===========================================
- Coverage    60.71%   60.66%   -0.06%     
===========================================
  Files          527      527              
  Lines        37091    37090       -1     
===========================================
- Hits         22520    22499      -21     
- Misses       11335    11358      +23     
+ Partials      3236     3233       -3