feat(Order/OmegaCompletePartialOrder): least fixed point and Scott induction

[tannerduve]

Add lfp for endomorphisms on an ωCPO with a least element and its basic API (map_lfp, isFixedPt_lfp, lfp_le_fixed, isLeast_lfp) and the Scott induction theorem lfp_induction

Also add corresponding induction principles for Part.fix: fix_scott_induction (ω-Scott continuous functional, admissible predicate) and fix_scott_induction_pointwise

[github-actions]

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[github-actions]

PR summary 98261a9c88

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff

+ exists_mem_approx_of_mem_fix
+ fix_eq_lfp
+ fix_scott_induction
+ fix_scott_induction_pointwise
+ isFixedPt_lfp
+ isLeast_lfp
+ lfp
+ lfp_induction
+ lfp_le_fixed
+ map_lfp

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).