chore(Combinatorics/SimpleGraph/Coloring): move ConcreteColorings.lean and EdgeLabeling.lean to Coloring/

[SnirBroshi]

Moves SimpleGraph/ConcreteColorings.lean to SimpleGraph/Coloring/Constructions.lean
and SimpleGraph/EdgeLabeling.lean to SimpleGraph/Coloring/EdgeLabeling.lean.

See Zulip

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Zulip might want to rename ConcreteColorings (Edit: the poll chose Constructions.lean)

#37546 adds module deprecations

[github-actions]

PR summary 63868fe5ba

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference
Mathlib.Combinatorics.SimpleGraph.ConcreteColorings	-990
Mathlib.Combinatorics.SimpleGraph.EdgeLabeling	-570
Mathlib.Combinatorics.SimpleGraph.Coloring.EdgeLabeling	570
Mathlib.Combinatorics.SimpleGraph.Coloring.Constructions	990

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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.

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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).

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note: file Mathlib/Combinatorics/SimpleGraph/EdgeLabeling.lean` was renamed to `Mathlib/Combinatorics/SimpleGraph/Coloring/EdgeLabeling.lean without a module deprecation
Please create a follow-up pull request adding one. Thanks!

note: file Mathlib/Combinatorics/SimpleGraph/ConcreteColorings.lean` was renamed to `Mathlib/Combinatorics/SimpleGraph/Coloring/Constructions.lean without a module deprecation
Please create a follow-up pull request adding one. Thanks!