Various WebCrypto improvements #7200

Job	Run time
Lagom (Linux, ubuntu-24.04, NO_FUZZ, GNU, false) / CI	48m 7s
Lagom (Linux, ubuntu-24.04, FUZZ, Clang, false) / CI	19m 39s
Lagom (Linux, ubuntu-24.04, NO_FUZZ, Clang, true) / CI	35m 32s
Lagom (macOS, macos-15, NO_FUZZ, Clang, false) / CI	36m 26s
	2h 19m 44s

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