Get ready for beta 5

[danielSanchezQ]

• Fixed missing calls to decode
• Fixed double free bug on creating topics
• Updated vendor
• Updated dependencies
• Added Dns discovery info

[richard-ramos]

If possible, please use this go-waku commit 4804588197c3626b8a19b3c200774b04ecb08fde as it includes a fix for the relayTopics config item being ignored