feat: Module theory theorems

[abeldonate]

Added three theorems:

• annihilator_sup
• torsionOf_eq_annihilator_span_singleton
• annihilator_eq_iInf_torsionOf

[github-actions]

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[github-actions]

PR summary 6bc2280e53

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff

+ _root_.Module.annihilator_eq_iInf_torsionOf
+ annihilator_sup
+ torsionOf_eq_annihilator_span_singleton

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.

---

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).

[wwylele]

As the CI error shows, this breaks simp in some other files so it might not be a good global simp lemma

[abeldonate]

I think it broke some other files because of the namespace I was using, now it should be fixed.

[scholzhannah]

Thank you for your PR! I have left some comments on style.

[scholzhannah]

Suggested change

	torsionOf R M x = (Submodule.span R ({x} : Set M)).annihilator := by
	have := (Submodule.annihilator_span_singleton (R := R) (M := M) x).symm
	simpa [torsionOf]
	torsionOf R M x = (Submodule.span R ({x} : Set M)).annihilator :=
	(Submodule.annihilator_span_singleton x).symm

I'm not 100% sure if we want this lemma given that it is just restating Submodule.annihilator_span_singleton but I think it is probably still useful for discoverability.