[Swift] Adds new API to reduce memory copying within swift #6674

Job	Run time
Build Android (on Linux)	3m 20s
Build Benchmarks (on Linux) (g++-13)	2m 47s
Build Windows C++ (11)	4m 22s
Build Dart	1m 10s
Build Windows C++ (14)	4m 34s
Build Windows C++ (17)	4m 8s
Build .NET Windows	1m 34s
Check Generated Code (g++-13)	1m 2s
Build Windows C++ (20)	5m 42s
Check Generated Code on Windows	4m 37s
Check Generated Code (clang++-18)	1m 14s
Build Windows C++ (23)	5m 48s
Build .NET Windows (-p:UnsafeByteBuffer=true)	1m 33s
Build Go	1m 14s
Build Java	16s
Build Kotlin Linux	3m 6s
Build Kotlin MacOS	4m 52s
Build Linux (g++-13)	1m 48s
Build Linux (clang++-18)	2m 7s
Build Linux C++ (11, g++-13)	1m 48s
Build Linux with -DFLATBUFFERS_NO_FILE_TESTS	2m 0s
Build Linux with out-of-source build location	1m 10s
Build Linux C++ (11, clang++-18)	2m 0s
Build Linux C++ (14, g++-13)	1m 48s
Build Mac (for Intel)	1m 29s
Build Mac (universal build)	1m 53s
Build Linux C++ (14, clang++-18)	1m 59s
Build Nim	1m 13s
Build Linux C++ (17, g++-13)	1m 57s
Build PHP	56s
Build Python	56s
Build Rust Linux	1m 50s
Build Linux C++ (17, clang++-18)	2m 8s
Build Rust Windows	1m 34s
Build Swift (5.8)	2m 1s
Build Swift Wasm	3m 13s
Build Linux C++ (20, g++-13)	2m 7s
Build Swift (5.9)	2m 21s
Build Linux C++ (20, clang++-18)	2m 25s
Build TS	1m 21s
Build Swift (5.10)	2m 16s
Build Windows 2019	4m 27s
Build Linux C++ (23, g++-13)	2m 6s
release-digests	0s
provenance	0s
	1h 42m 12s

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