Testsuite: avoid using existing e-mail addresses and domains in tests.

tests/address.svtest

tests/comparators/core.svtest

tests/compile/errors/address-part.sieve

tests/compile/errors/envelope.sieve

tests/compile/errors/match-type.sieve

tests/compile/errors/out-address.sieve

tests/compile/errors/unsupported.sieve

tests/compile/recover/commands-semicolon.sieve

tests/compile/redirect.sieve

tests/compile/warnings/invalid-headers.sieve

tests/control-structures.svtest

tests/deprecated/notify/basic.svtest

tests/deprecated/notify/denotify.svtest

tests/deprecated/notify/errors/options.sieve

tests/deprecated/notify/execute/duplicates.sieve

tests/deprecated/notify/mailto.svtest

tests/execute/actions.svtest

tests/execute/actions/fileinto.sieve

tests/execute/actions/redirect.sieve

tests/execute/mailstore.svtest