Rename blowdown to blowup

[paemurru]

Command used:

sed --follow-symlinks -i \
-e "s;blowdown;blowup;g" \
-e "s;blow-down;blow-up;g" \
-e "s;Blow-down;Blow-up;g" \
-e "s;Blowdown;Blowup;g" \
-e "s;BlowDown;BlowUp;g" \
$(git ls-files)

mv "./test/AlgebraicGeometry/ToricVarieties/toric_blowdowns.jl" "./test/AlgebraicGeometry/ToricVarieties/toric_blowups.jl"
mv "./docs/src/AlgebraicGeometry/ToricVarieties/BlowdownMorphisms.md" "./docs/src/AlgebraicGeometry/ToricVarieties/BlowupMorphisms.md"

[codecov]

Codecov Report

Attention: Patch coverage is 62.12121% with 25 lines in your changes missing coverage. Please review.

Project coverage is 84.65%. Comparing base (d91db2a) to head (4ad9d7e).
Report is 3 commits behind head on master.

Files with missing lines	Patch %	Lines
experimental/Schemes/src/BlowupMorphism.jl	55.55%	12 Missing ⚠️
experimental/Schemes/src/ToricBlowups/types.jl	57.89%	8 Missing ⚠️
...xperimental/Schemes/src/ToricBlowups/attributes.jl	80.00%	2 Missing ⚠️
experimental/FTheoryTools/src/auxiliary.jl	50.00%	1 Missing ⚠️
...erimental/Schemes/src/ToricBlowups/constructors.jl	80.00%	1 Missing ⚠️
experimental/Schemes/src/ToricBlowups/methods.jl	50.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4148   +/-   ##
=======================================
  Coverage   84.65%   84.65%           
=======================================
  Files         626      626           
  Lines       84316    84316           
=======================================
  Hits        71380    71380           
  Misses      12936    12936           

Files with missing lines	Coverage Δ
experimental/Schemes/src/Resolution_structure.jl	67.53% <100.00%> (ø)
...y/Schemes/CoveredSchemes/Morphisms/Constructors.jl	95.45% <ø> (ø)
...ometry/ToricVarieties/ToricMorphisms/attributes.jl	80.21% <ø> (ø)
experimental/FTheoryTools/src/auxiliary.jl	76.00% <50.00%> (ø)
...erimental/Schemes/src/ToricBlowups/constructors.jl	89.83% <80.00%> (ø)
experimental/Schemes/src/ToricBlowups/methods.jl	50.00% <50.00%> (ø)
...xperimental/Schemes/src/ToricBlowups/attributes.jl	93.54% <80.00%> (ø)
experimental/Schemes/src/ToricBlowups/types.jl	71.92% <57.89%> (ø)
experimental/Schemes/src/BlowupMorphism.jl	89.63% <55.55%> (ø)

... and 1 file with indirect coverage changes

[afkafkafk13]

Looks good to me. Ping @HereAround for the toric side, please. (In case of his approval, this can be merged.)

[afkafkafk13]

Do we need to deprecate to save some code that people have written but not merged yet?

[HechtiDerLachs]

I'm afraid that an n-th layer of deprecation is necessary. Maybe we can even roll back in some cases? I don't know how to handle this. Other than that, I'm ok with the changes.

[lgoettgens]

From a purely technical POV, deprecations are not necessary here, as there are no (non-comment) changes to src/, and no changes to the book.
However, adding deprecations for things in experimental/ is still a nice convenience for users.

(cc @lkastner)

[mjrodgers]

Discussed in triage, looks okay to merge.