feat(Convex): the set of concave/convex functions on a given set is closed

[dupuisf]

This PR proves that the set of concave/convex functions on a set s is closed.

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AI use: this was my first attempt at using Aristotle. It found a proof in ~15 mins, but I had to generalise and clean it up quite a bit (it only did it for real vector spaces).

[github-actions]

PR summary 34f85c5f24

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference
Mathlib.Analysis.Convex.FunctionTopology (new file)	1173

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Declarations diff

+ OrderDual.instContinuousSMul_left
+ OrderDual.instContinuousSMul_right

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).