feat: Implement proposer component

[infrmtcs]

No description provided.

[codecov]

Codecov Report

Attention: Patch coverage is 77.50000% with 36 lines in your changes missing coverage. Please review.

Project coverage is 72.25%. Comparing base (f950632) to head (67038c1).
Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
consensus/proposer/proposer.go	73.68%	23 Missing and 7 partials ⚠️
builder/executor.go	0.00%	2 Missing and 1 partial ⚠️
builder/state.go	92.50%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2947      +/-   ##
==========================================
+ Coverage   72.19%   72.25%   +0.06%     
==========================================
  Files         262      263       +1     
  Lines       28368    28572     +204     
==========================================
+ Hits        20479    20645     +166     
- Misses       6496     6526      +30     
- Partials     1393     1401       +8     

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[rianhughes]

I think we should really keep track of the fact our pending block does not have proper read-write controls. I've created an issue to track this here #2957. This is a bigger issue that is outside the scope of this PR imo