More generic impl of Replacer for closures #1746

Job	Run time
testfull-regex	6m 39s
msrv	1m 27s
test (stable, ubuntu-latest, stable)	7m 1s
test (stable-32, ubuntu-latest, stable, i686-unknown-linux-gnu)	4m 54s
test (stable-mips, ubuntu-latest, stable, mips64-unknown-linux-gnuabi64)	11m 7s
test (beta, ubuntu-latest, beta)	7m 22s
test (nightly, ubuntu-latest, nightly)	7m 3s
test (macos, macos-latest, stable)	7m 43s
test (win-msvc, windows-latest, stable)	12m 38s
test (win-gnu, windows-latest, stable-x86_64-gnu)	5m 53s
miri-regex-automata	13m 39s
rustfmt	19s
testfull-regex-automata	17m 43s
testfull-regex-syntax	3m 32s
testfull-regex-capi	42s
	1h 47m 42s

Provide feedback