This change is needed so that the `libwaku.nim` code gets simpler. The
`libwaku.nim` can't import the 'WakuNodeConf' type because this is
related to the wakunode2 app, and the library shouldn't know about it.
- Remove discv5 from node and it's builder
- Require a record to init a node (was previously using discv5 record).
- Fix various tests that assumed nodes with discv5.
- Fix ENR creation
- Fix wakubridge
- Fix networkmonitor