Add standard_form modifications

[odow]

Closes #1890

I have deprecated set_coefficient in favor of set_standard_form_coefficient.

[codecov]

Codecov Report

Merging #1935 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #1935      +/-   ##
==========================================
+ Coverage   91.06%   91.07%   +<.01%     
==========================================
  Files          32       32              
  Lines        3950     3954       +4     
==========================================
+ Hits         3597     3601       +4     
  Misses        353      353

Impacted Files	Coverage Δ
src/constraints.jl	90.75% <100%> (+0.15%)	⬆️
src/macros.jl	93% <0%> (+0.02%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update b88eb99...44114e9. Read the comment docs.

[codecov]

Codecov Report

Merging #1935 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #1935      +/-   ##
==========================================
+ Coverage   91.06%   91.07%   +<.01%     
==========================================
  Files          32       32              
  Lines        3950     4256     +306     
==========================================
+ Hits         3597     3876     +279     
- Misses        353      380      +27

Impacted Files	Coverage Δ
src/constraints.jl	91.05% <100%> (+0.45%)	⬆️
src/quad_expr.jl	92.03% <100%> (+1.19%)	⬆️
src/aff_expr.jl	94.08% <100%> (+1.52%)	⬆️
src/operators.jl	82.38% <0%> (-1.66%)	⬇️
src/macros.jl	93% <0%> (+0.02%)	⬆️
src/variables.jl	97.9% <0%> (+0.21%)	⬆️
src/objective.jl	96.29% <0%> (+1.29%)	⬆️
src/Containers/DenseAxisArray.jl	85.98% <0%> (+4.07%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update b88eb99...8305c2d. Read the comment docs.

[mlubin]

What do you think about corresponding getters standard_form_coefficient and standard_form_rhs?

[blegat]

I don't support renaming set_coefficient to set_standard_form_coefficient`.
The "standard form" is confusing because of the confusion with https://en.m.wikipedia.org/wiki/Linear_programming#Standard_form

[odow]

Not sure if this counts as breaking because it adds deprecations.

[blegat]

Do you think it should be included in v0.19.1 ?

[odow]

I don't mind. It isn't urgent, so it can probably wait. (Selfish reason, I'll have to update SDDP.jl, and relying on a patch 0.19.1 isn't fun.)

[blegat]

Even if there is warning, if someone release a package using this function and people use this package, when updating JuMP, the package will throw warning so it is kind of breaking.
I'd like to release MOI v0.9 in a few days so if we give a week for packages to update to it, we can release JuMP v0.20 in about a week.