Derive `Ord` and `PartialOrd` for `ClassName` #2897

Job	Run time
clippy	1m 51s
license-guard	38s
doc-lints	49s
godot-itest (macos)	1m 5s
run-examples	1m 19s
godot-itest (windows)	2m 45s
rustfmt	18s
godot-itest (linux-full)	2m 36s
unit-test	2m 28s
godot-itest (linux-features-experimental)	2m 30s
godot-itest (linux-4.1)	1m 32s
godot-itest (linux-4.2)	1m 25s
godot-itest (linux-memcheck)	2m 24s
ci-status	1s
	21m 41s

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