feat(Data/Finset/Image): add lemmas linking Finset.image with MapsTo/SurjOn/InjOn

[b-mehta]

and also with Nat.iterate.

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[github-actions]

PR summary 4fceb4697e

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

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Declarations diff

+ image_eq_iff_surjOn_mapsTo
+ iterate_image
+ mapsTo_iff_image_subset
+ surjOn_iff_subset_image

You can run this locally as follows

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

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

The doc-module for scripts/pr_summary/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/reporting/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).

[riccardobrasca]

#Thanks!

bors d+

[mathlib-bors]

✌️ b-mehta can now approve this pull request. To approve and merge a pull request, simply reply with bors r+. More detailed instructions are available here.

[mathlib-auto-merge]

As this PR is labelled auto-merge-after-CI, we are now sending it to bors:

bors merge