Log hapi log tags as the new dedicated tags

**Is your feature request related to a problem? Please describe.**
Right now it logs under `context.custom.tags` while there is a dedicated `context.tags`
https://github.com/elastic/apm-agent-nodejs/blob/cbf39df9ebd68d29f136cfeb40cb5b6f8b099073/lib/instrumentation/modules/hapi.js#L91

**Describe the solution you'd like**
Log it to `context.tags` so I can query on it 🎉

**Describe alternatives you've considered**
in a filter do
```js
if (item.exception && item.context.custom.tags) {
item.context.tags = { ...item.context.tags, ...item.context.custom.tags };
}
```

**Additional context**
Add any other context or screenshots about the feature request here.