refactor(MeasureTheory): golf Mathlib/MeasureTheory/Function/AEEqOfIntegral

[yuanyi-350]

• refactors MeasureTheory/Function/AEEqOfIntegral by reusing the AEFinStronglyMeasurable zero-integral criterion for the integrable case
• rewrites the integrable set-integral equality lemmas to delegate to the AEFinStronglyMeasurable versions instead of rebuilding the Lp and subtraction arguments inline

Extracted from #38104

[github-actions]

PR summary ee3a5404e5

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

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/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.

This script lives in the mathlib-ci repository. To run it locally, from your mathlib4 directory:

git clone https://github.com/leanprover-community/mathlib-ci.git ../mathlib-ci
../mathlib-ci/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).

[yuanyi-350]

I ran a profiler comparison for the changed declarations in this PR.

Results (seconds, top-level command times):

• MeasureTheory.Integrable.ae_eq_zero_of_forall_setIntegral_eq_zero: 0.025877 -> 0.024470 (-5.44%)
• MeasureTheory.Integrable.ae_eq_of_forall_setIntegral_eq: 0.015411 -> 0.014461 (-6.16%)

Overall:

• Both changed declarations are slightly faster.

[yuanyi-350]

!bench

[leanprover-radar]

Benchmark results for 66ccf0a against ee3a540 are in. No significant results found. @yuanyi-350

• 🟥 build//instructions: +9.1G (+0.01%)

Small changes (1🟥)

• 🟥 build/module/Mathlib.Tactic.MinImports//instructions: +136.1M (+2.71%)