Rework Vector_softRemove() and compact() operations #5358

Job	Run time
build-ubuntu-latest-minimal-gcc	41s
build-ubuntu-latest-minimal-clang	1m 26s
lint-pcp-config	4s
build-freebsd-latest-clang	1m 57s
build-solaris-latest-gcc	8m 0s
build-ubuntu-latest-clang-sanitizer	1m 21s
build-macos-latest-clang	1m 1s
build-ubuntu-latest-full-featured-clang	2m 52s
build-ubuntu-latest-gcc-static	1m 0s
build-ubuntu-latest-clang-analyzer	1m 49s
build-dragonflybsd-latest-gcc	2m 39s
build-unsupported-latest-gcc	28s
build-openbsd-latest-clang	2m 56s
build-netbsd-latest-gcc	4m 29s
build-ubuntu-latest-full-featured-gcc	1m 5s
lint-whitespace	5s
build-ubuntu-latest-pcp	42s
	32m 35s

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