[Merged by Bors] - chore(Algebra/Group/Pointwise/{Fin}set/Basic): split files

[BoltonBailey]

This PR splits the files on pointwise operations on sets, creating new files for the scalar multiplication etc. operations.

This addresses an instance of the long file linter, while keeping the directory structure analogous.

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[github-actions]

PR summary 484ff183d1

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference
There are 3042 files with changed transitive imports taking up over 136350 characters: this is too many to display!
You can run scripts/import_trans_difference.sh all locally to see the whole output.

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Declarations diff

No declarations were harmed in the making of this PR! 🐙

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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Decrease in tech debt: (relative, absolute) = (1.00, 0.07)

Current number	Change	Type
14	-1	large files

Current commit 484ff183d1
Reference commit 44dc3a3a60

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).

[kim-em]

bors merge

[mathlib-bors]

Pull request successfully merged into master.

Build succeeded:

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