[FTheoryTools] More on serialization of FTheoryTools

[HereAround]

As mentioned in the other PRs, it seemed natural to group all the different serialization discussions we had in one PR. For this, I need your help @antonydellavecchia whenever you are ready (not urgent).

Points to be addressed in this PR include (but are not necessarily limited to the following):

• The coordinates of the base space and ambient space should be remembered upon serialization. I will try to add a first step towards this goal in this PR/draft. As I see it, this requires that we add a list of strings (or symbols?) to the serialization of the models. An update of the QSM model artifacts is then needed.
• Along these lines, we could also consider serialzing G4-fluxes (a.k.a. cohomology classes on toric spaces). At least for the QSMs, there is each time a specifically chosen G4-fluxes (cf. https://arxiv.org/pdf/2102.10115, equ. 2.25).
• Maybe wait for Serialization of Lie algebras #3980 and include the Lie algebras of the FTheoryModels in the serialization. In particular, this should be also applied to the QSM models.
• Add an artifact for the model discussed in [FTheoryTools] Add model 1511.03209 #3978. I have the corresponding .mrdi files and will be happy to share e.g. in slack or email. (This cannot be added here as github does not seem to support .mrdi files yet. And then, the files are about 0.5GB in size. So maybe best not to add them here.)
• Make use of the attribute saver that @antonydellavecchia is working on (cf. Serialize Types with Attributes #4020). For instance, currently the known resolutions are not saved for FTheory models.

cc @antonydellavecchia @emikelsons @apturner

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.70%. Comparing base (97bc0a4) to head (82437b0).
Report is 8 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4008      +/-   ##
==========================================
+ Coverage   84.65%   84.70%   +0.04%     
==========================================
  Files         614      614              
  Lines       83344    83586     +242     
==========================================
+ Hits        70554    70798     +244     
+ Misses      12790    12788       -2     

Files with missing lines	Coverage Δ
...TheoryTools/src/HypersurfaceModels/constructors.jl	96.72% <100.00%> (ø)
...eoryTools/src/Serialization/hypersurface_models.jl	100.00% <100.00%> (ø)
...ntal/FTheoryTools/src/Serialization/tate_models.jl	97.43% <ø> (ø)
...heoryTools/src/Serialization/weierstrass_models.jl	97.91% <100.00%> (+0.48%)	⬆️

... and 16 files with indirect coverage changes