xilem_web: Add MemoizedStream view #2256

Job	Run time
cargo clippy (wasm32)	48s
cargo check (aarch64-android)	28s
cargo clippy (windows-latest)	42s
formatting	30s
cargo clippy (macos-latest)	1m 19s
cargo test (wasm32)	19s
cargo clippy (ubuntu-latest)	31s
cargo check (msrv) (windows-latest)	1m 25s
cargo check (msrv) (wasm32)	18s
cargo check (msrv) (macos-latest)	40s
cargo doc	28s
cargo check (msrv) (ubuntu-latest)	45s
Prime LFS Cache	8s
typos	7s
cargo test (windows-latest)	1m 29s
cargo test (macos-latest)	44s
cargo test (ubuntu-latest)	1m 27s
	12m 8s

Provide feedback