Add PreviousState Resource accessible in OnEnter #72126

Job	Run time
miri	23m 31s
check-doc	10m 53s
toml	8s
check-missing-examples-in-docs	36s
typos	9s
ci	5m 39s
build (ubuntu-latest)	12m 6s
build (macos-latest)	21m 22s
check-bevy-internal-imports	5s
build (windows-latest)	21m 38s
check-release-content	44s
check-missing-features-in-docs	27s
markdownlint	1m 25s
check-compiles-no-std-examples	1m 7s
check-compiles	8m 41s
check-compiles-no-std	1m 23s
check-compiles-no-std-portable-atomic	1m 9s
build-wasm-atomics	1m 51s
build-wasm	1m 47s
msrv	3m 22s
	1h 58m 3s

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