Resolve unbound type parameters

[fingolfin]

This also removes some of the ambiguities for direct_product,
direct_sum, tensor_product with empty argument list.

Re-enable Aqua test for unbound type parameters.

[lgoettgens]

Missing docstring for direct_sum(M::ModuleFP{T}...; task::Symbol = :sum) where T. Check Documenter's build log for details.' in @docs block in src/CommutativeAlgebra/ModulesOverMultivariateRings/module_operations.md:29-31

I think you need to update the docstring signature at this place as well

[fingolfin]

The changed docstring is caused by the attribute direct_product changing from a Tuple to a Vector, and it gets printed raw by this function:

function Hecke.show_direct_sum(io::IO, G)
  D = get_attribute(G, :direct_product)
  D === nothing && error("only for direct sums")
  print(io, "direct sum of ")
  show(IOContext(io, :compact => true), D)
end

For nicer printing, that function (and its siblings around it) should be improved.

That leave the question whether the change from tuple to vector is fine. I had a quick look at the code using this attribute and I believe it is all fine either. Long term a vector IMO makes more sense there.

CC @HechtiDerLachs

[HechtiDerLachs]

Looks fine from my side, if the tests pass.

It seems that most of the relevant changes were for the modules and only revealed in my code because I use them. I'm afraid, I'm not qualified to change the printing of modules myself.

[codecov]

Codecov Report

Attention: Patch coverage is 82.60870% with 4 lines in your changes missing coverage. Please review.

Project coverage is 84.39%. Comparing base (ba3a8ac) to head (9b802ac).
Report is 101 commits behind head on master.

Files with missing lines	Patch %	Lines
...leAndHyperComplexes/src/Objects/tensor_products.jl	33.33%	4 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4363   +/-   ##
=======================================
  Coverage   84.39%   84.39%           
=======================================
  Files         668      668           
  Lines       88557    88567   +10     
=======================================
+ Hits        74736    74747   +11     
+ Misses      13821    13820    -1     

Files with missing lines	Coverage Δ
experimental/GModule/src/Cohomology.jl	73.66% <100.00%> (+0.08%)	⬆️
...gebraicGeometry/Schemes/Sheaves/CoherentSheaves.jl	81.21% <ø> (ø)
src/Modules/UngradedModules/DirectSum.jl	85.07% <100.00%> (+0.69%)	⬆️
...leAndHyperComplexes/src/Objects/tensor_products.jl	90.56% <33.33%> (ø)

... and 1 file with indirect coverage changes