Replace deprecated options in `outputs.wavefront`

Replace the following options in the plugin and provide a migration
```
  outputs.wavefront/host                   ERROR since 1.28.0 removal in 1.35.0 use url instead
  outputs.wavefront/port                   ERROR since 1.28.0 removal in 1.35.0 use url instead
  outputs.wavefront/string_to_number       ERROR since 1.9.0 removal in 1.35.0 use the enum processor instead
```