feat(gcongr): support @[gcongr] for Monotone and friends

[JovanGerb]

This PR adds the feature to gcongr that you can now tag lemmas whose conclusion is Monotone f, Antitone f, etc.

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[github-actions]

PR summary dde1cfffb6

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

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Declarations diff

+ myAnti
+ myAnti_strictAnti
+ myAnti_strictAntiOn
+ myCons
+ myCons_antitone
+ myCons_antitoneOn
+ myCons_monotone
+ myCons_monotone'
+ myCons_monotoneOn
+ myMono
+ myMono_strictMono
+ myMono_strictMonoOn
- GCongr.algebraMap_le_algebraMap
- GCongr.algebraMap_lt_algebraMap
- GCongr.intCast_mono
- GCongr.mapDomain_mono
- GCongr.mono
- _root_.GCongr.Filter.comap_le_comap
- _root_.GCongr.Filter.map_le_map
- _root_.GCongr.coheight_le_coheight
- _root_.GCongr.height_le_height
- _root_.GCongr.natCast_le_natCast
- _root_.GCongr.natCast_lt_natCast
- ruzsaSzemerediNumberNat_le_ruzsaSzemerediNumberNat

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.

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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).

[kckennylau]

Thanks!

[mathlib4-merge-conflict-bot]

This pull request has conflicts, please merge master and resolve them.

[mathlib4-merge-conflict-bot]

This pull request has conflicts, please merge master and resolve them.

[Vierkantor]

I was confused for a brief moment why only some lemmas got a deprecation, but the ones that were deleted outright are all in the GCongr namespace. So that's good!

One question about the implementation strategy, otherwise the code is very neat!