chore(Order/Def): avoid relying on internal class projections in other files

[JovanGerb]

This PR removes references to lemmas that are class projections of Preorder, PartialOrder or LinearOrder. Instead, the global namespace lemmas should be used. To avoid accidentally referring to these lemmas, they are marked as protected.

I hope that it will be possible to hide these lemmas from the imports, using the module system. See https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Should.20duplicated.20class.20projections.20be.20private.3F/with/558208782

---

[github-actions]

PR summary 5db554c938

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff

+ ge_antisymm
+ ge_trans

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.

---

No changes to technical debt.

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).