refactor: use tastora spamoor and victoriatraces implementations

Replace local spamoor_node.go and victoriatraces_node.go with tastora's
spamoor.NewNodeBuilder and victoriatraces.New. Fixes macOS compatibility
by replacing 0.0.0.0 with 127.0.0.1 for external endpoints and using
UTC timestamps in trace query URLs to avoid broken timezone offsets.

Author: chatton