fix: dev: Simplify some dns_name API calls

Several functions in the `dns_name` module have had parameters removed, that were rarely or never used:
- `dns_name_fromtext()` and `dns_name_concatenate()` no longer take a target buffer.
- `dns_name_towire()` no longer takes a compression offset pointer; this is now part of the compression context.
- `dns_name_towire()` with a `NULL` compression context will copy name data directly into a buffer with no processing.

Merge branch 'each-simplify-names' into 'main'

See merge request isc-projects/bind9!10152