feat(Analysis/NormedSpace/MStructure): M-ideals

[mans0954]

WiP: Define M-ideals and establish basic properties.

---

• depends on: [Merged by Bors] - feat(Analysis/LocallyConvex/Polar): Calculate the polar of a set closed under scalar multiplication #14458

[github-actions]

PR summary 9a6c14b41a

Import changes exceeding 2%

%	File
+74.67%	Mathlib.Analysis.NormedSpace.MStructure

Import changes for modified files

Dependency changes

File	Base Count	Head Count	Change
Mathlib.Analysis.NormedSpace.MStructure	979	1710	+731 (+74.67%)

Import changes for all files

Files	Import difference
Mathlib.Analysis.NormedSpace.MStructure	731

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Declarations diff

+ IsIdempotentElem.range_prod__of_commute
+ IsLprojection.range_inter
+ IsLprojection.range_sum
+ IsMideal
+ IsMideal.inter
+ IsMideal.isSublattice
+ contractive
+ instance : FunLike Pₗ[𝕜](A) A A
+ polarSubmodule
+ polarSubmodule_eq_polar
+ proj_apply
+ range_prod_of_commute
+ unit_ball_conv

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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Increase in tech debt: (relative, absolute) = (1.00, 0.10)

Current number	Change	Type
10	1	maxHeartBeats modifications

Current commit 9a6c14b41a
Reference commit 2bb0410843

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).

[leanprover-community-mathlib4-bot]

This PR/issue depends on:

• [Merged by Bors] - feat(Analysis/LocallyConvex/Polar): Calculate the polar of a set closed under scalar multiplication #14458
  By Dependent Issues (🤖). Happy coding!