Remove filter shutdown

dapps/valuetransfers/packages/tangle/signature_filter.go

.../messageparser/builtinfilters/message_signature_filter.go

...y/messagelayer/messageparser/builtinfilters/pow_filter.go

...sagelayer/messageparser/builtinfilters/pow_filter_test.go

...essageparser/builtinfilters/recently_seen_bytes_filter.go

packages/binary/messagelayer/messageparser/bytes_filter.go

packages/binary/messagelayer/messageparser/message_filter.go

packages/binary/messagelayer/messageparser/message_parser.go

.../binary/messagelayer/messageparser/message_parser_test.go

plugins/messagelayer/plugin.go