Added address normalization to prevent redirect action duplicates.

sieve/tests/actions.sieve

src/lib-sieve/cmd-redirect.c

src/lib-sieve/ext-encoded-character.c

src/lib-sieve/plugins/copy/ext-copy.c

src/lib-sieve/plugins/vacation/cmd-vacation.c

src/lib-sieve/sieve-address.c

src/lib-sieve/sieve-address.h

src/lib-sieve/sieve-ast.c

src/lib-sieve/sieve-ast.h

src/lib-sieve/sieve-result.c