Implement global MeanField and BetheFactorization constraints

[wouterwln]

No description provided.

[bvdmitri]

Great! Could you please also copy the new docstrings for MeanField and BetheFactorization from ReactiveMP (the one from @Raphael-Tresor)?

[bvdmitri]

I think its only valid for constraints::Constraints, right?
Also we could add

function apply_constraints!(
    model::Model,
    context::Context,
    constraint::UnspecifiedConstraints
)
    nothing 
end

or even remove UnspecifiedConstraints in the favour of BetheFactorization?

[wouterwln]

I feel that UnspecifiedConstraints should still use the default_constraints, if any are specified, whereas BetheFactorization overrides these constraints in favour of the Bethe Factorization

[codecov]

Codecov Report

Attention: Patch coverage is 85.71429% with 2 lines in your changes are missing coverage. Please review.

Project coverage is 91.69%. Comparing base (e199e5b) to head (569b2ec).
Report is 26 commits behind head on dev-4.0.0.

Files	Patch %	Lines
...onal_constraints/variational_constraints_engine.jl	81.81%	2 Missing ⚠️

Additional details and impacted files

@@              Coverage Diff              @@
##           dev-4.0.0     #172      +/-   ##
=============================================
+ Coverage      91.34%   91.69%   +0.35%     
=============================================
  Files             14       14              
  Lines           1733     1795      +62     
=============================================
+ Hits            1583     1646      +63     
+ Misses           150      149       -1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.