Add Variable.RSOCtoPSD

[blegat]

Extracted from #759

[codecov-io]

Codecov Report

Merging #821 into master will increase coverage by 0.23%.
The diff coverage is 95.38%.

@@            Coverage Diff             @@
##           master     #821      +/-   ##
==========================================
+ Coverage   93.13%   93.36%   +0.23%     
==========================================
  Files          68       69       +1     
  Lines        7504     7570      +66     
==========================================
+ Hits         6989     7068      +79     
+ Misses        515      502      -13

Impacted Files	Coverage Δ
src/Bridges/Variable/Variable.jl	100% <ø> (ø)	⬆️
src/Bridges/Variable/rsoc_to_psd.jl	95.38% <95.38%> (ø)
src/Bridges/Variable/map.jl	98.46% <0%> (+0.76%)	⬆️
src/sets.jl	94.44% <0%> (+1.38%)	⬆️
src/Bridges/bridge_optimizer.jl	86.44% <0%> (+4.27%)	⬆️

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