refactor(hydroflow_plus): dedup signatures for `Stream` operators (#1… #907

Job	Run time
pre_job	6s
windows (x86_64-pc-windows-msvc, x64)	10m 39s
linux-cross (aarch64-unknown-linux-gnu, aarch64)	3m 31s
linux-cross (armv7-unknown-linux-gnueabihf, armv7)	3m 44s
windows (i686-pc-windows-msvc, x86)	11m 27s
linux (x86_64-unknown-linux-gnu)	3m 25s
windows (aarch64-pc-windows-msvc, x64)	13m 46s
macos-universal (universal2-apple-darwin)	4m 2s
linux (i686-unknown-linux-gnu)	4m 47s
Release	0s
	55m 27s

Provide feedback