[Merged by Bors] - feat(CategoryTheory/Localization): liftings of bifunctors

[joelriou]

When a functor F : C ⥤ E inverts a class of morphisms W : MorphismProperty C and L : C ⥤ D is a localization functor for W, then F lifts as a functor D ⥤ E. In this PR, this is generalized to bifunctors (or "functors in two variables") F : C₁ ⥤ C₂ ⥤ E, which may be lifted as a functor D₁ ⥤ D₂ ⥤ E under similar assumptions.

(We shall also need a version of this in three variables.)

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[github-actions]

PR summary a3f5186238

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference
Mathlib.CategoryTheory.Localization.Bifunctor (new file)	417

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Declarations diff

+ IsInvertedBy₂
+ Lifting₂
+ Lifting₂.flip
+ Lifting₂.fst
+ Lifting₂.iso
+ Lifting₂.liftingLift₂
+ Lifting₂.liftingLift₂Flip
+ Lifting₂.snd
+ Lifting₂.uncurry
+ curryObjProdComp
+ flipFunctor
+ fullyFaithfulUncurry
+ hom_inv_id_app_app
+ instance : (uncurry : (C ⥤ D ⥤ E) ⥤ C × D ⥤ E).Faithful
+ instance : (uncurry : (C ⥤ D ⥤ E) ⥤ C × D ⥤ E).Full
+ instance : Lifting₂ L₁ L₂ W₁ W₂ F (lift₂ F hF L₁ L₂)
+ inv_hom_id_app_app
+ lift₂
+ lift₂NatIso
+ lift₂NatTrans
+ lift₂NatTrans_app_app
+ lift₂_iso_hom_app_app₁
+ lift₂_iso_hom_app_app₂
+ natTrans₂_ext
+ whiskeringLeft₂

You can run this locally as follows

## summary with just the declaration names:
./scripts/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/declarations_diff.sh long <optional_commit>

The doc-module for script/declarations_diff.sh contains some details about this script.

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No changes to technical debt.

You can run this locally as

./scripts/technical-debt-metrics.sh pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).

[dagurtomas]

I am listed as a coauthor of the PR #12728 where this was developed, and I can confirm that the API works well there. I also did not contribute to this part, so:

maintainer merge

[github-actions]

🚀 Pull request has been placed on the maintainer queue by dagurtomas.

[jcommelin]

Thanks 🎉

bors merge

[mathlib-bors]

Pull request successfully merged into master.

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