feat(cluster): create a unified abstraction for subsystems

[numinnex]

Adds an Plane trait that is used to dispatch requests to different subsystems based on the plane demux logic (similarly to how StateMachine works).

[codecov]

Codecov Report

❌ Patch coverage is 2.51572% with 155 lines in your changes missing coverage. Please review.
✅ Project coverage is 68.51%. Comparing base (ae484ec) to head (1c6ec0b).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
core/consensus/src/plane_mux.rs	0.00%	56 Missing ⚠️
core/common/src/types/consensus/header.rs	0.00%	55 Missing ⚠️
core/simulator/src/lib.rs	0.00%	11 Missing ⚠️
core/simulator/src/replica.rs	0.00%	11 Missing ⚠️
core/metadata/src/impls/metadata.rs	0.00%	9 Missing ⚠️
core/partitions/src/iggy_partitions.rs	0.00%	9 Missing ⚠️
core/common/src/types/consensus/message.rs	50.00%	4 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #2780      +/-   ##
============================================
- Coverage     68.65%   68.51%   -0.14%     
  Complexity      656      656              
============================================
  Files           742      743       +1     
  Lines         62688    62808     +120     
  Branches      59101    59221     +120     
============================================
- Hits          43036    43034       -2     
- Misses        17535    17657     +122     
  Partials       2117     2117              

Flag	Coverage Δ
rust	69.58% <2.51%> (-0.15%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
core/metadata/src/stm/mux.rs	91.35% <ø> (ø)
core/simulator/src/deps.rs	0.00% <ø> (ø)
core/common/src/types/consensus/message.rs	60.38% <50.00%> (-0.95%)	⬇️
core/metadata/src/impls/metadata.rs	15.90% <0.00%> (-1.17%)	⬇️
core/partitions/src/iggy_partitions.rs	0.00% <0.00%> (ø)
core/simulator/src/lib.rs	0.00% <0.00%> (ø)
core/simulator/src/replica.rs	0.00% <0.00%> (ø)
core/common/src/types/consensus/header.rs	13.97% <0.00%> (-3.47%)	⬇️
core/consensus/src/plane_mux.rs	0.00% <0.00%> (ø)

... and 7 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.