set_parameter -> set_optimizer_attribute

[odow]

Closes #2149

[codecov]

Codecov Report

Merging #2150 into master will decrease coverage by 0.63%.
The diff coverage is 8.69%.

@@            Coverage Diff             @@
##           master    #2150      +/-   ##
==========================================
- Coverage   91.75%   91.12%   -0.64%     
==========================================
  Files          42       42              
  Lines        4075     4112      +37     
==========================================
+ Hits         3739     3747       +8     
- Misses        336      365      +29

Impacted Files	Coverage Δ
src/JuMP.jl	73% <0%> (-7.4%)	⬇️
src/optimizer_interface.jl	81.81% <100%> (ø)	⬆️
src/utils.jl	52.63% <0%> (-6.2%)	⬇️
src/parse_nlp.jl	90.38% <0%> (-4.62%)	⬇️
src/quad_expr.jl	92.81% <0%> (-1.23%)	⬇️
src/macros.jl	92.61% <0%> (-0.77%)	⬇️
src/aff_expr.jl	87.85% <0%> (-0.64%)	⬇️
src/mutable_arithmetics.jl	91.93% <0%> (+1.61%)	⬆️

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[blegat]

Looking forward, we would have set_optimizer_attribute, set_model_attribute, set_variable_attribute and set_constraint_attribute.
I may be redundant that we specify both in the function name and in the signature the different of attribute type.
Why not have a single set_attribute function with 4 different methods ?

[odow]

Why not have a single set_attribute function with 4 different methods ?

People can always just do MOI.set(model, attr, index, value), which is actually less characters.

The reason for making optimizer_attribute special is so that it lines up with optimizer_with_attributes and because passing a string is fundamentally different.

For non-optimizer attributes, we either have things like set_start_value, or, for the more obscure ones, people should use MOI.set and know what they are doing.

[odow]

Not sure what went wrong with coverage, because all of the lines I added got hit.