Queries for non-existent record type take long time to eventually time out

On macOS, an attempt to resolve name for which the particular record type doesn't exist, results in long (~30s) delay.

For example:

```
AsyncDNSResolver().queryA(name: "some.domain.without.A.record")
```

An investigation showed that adding the additional [`kDNSServiceFlagsReturnIntermediates`](https://developer.apple.com/documentation/dnssd/1823436-anonymous/kdnsserviceflagsreturnintermediates), to the [`DNSServiceQueryRecord` invocation](https://github.com/apple/swift-async-dns-resolver/blob/08c07ff31a745ee5e522ac10132fb4949834d925/Sources/AsyncDNSResolver/dnssd/DNSResolver_dnssd.swift#L147) fixes the delay problem. However, now the code has to handle the possibility that `CNAME` gets returned instead of the requested record type, thus requiring it to inspect the `rrclass` and `rrtype` returned to the innermost handler [here](https://github.com/apple/swift-async-dns-resolver/blob/08c07ff31a745ee5e522ac10132fb4949834d925/Sources/AsyncDNSResolver/dnssd/DNSResolver_dnssd.swift#L129). If `CNAME` is returned, the desired query should be repeated on that `CNAME`, otherwise an error should be generated.

PRs welcome if someone beats me to the implementation.

Tested with https://github.com/apple/swift-async-dns-resolver/releases/tag/0.4.0

Start in Sources/AsyncDNSResolver/dnssd/DNSResolver_dnssd.swift, especially the DNSServiceQueryRecord invocation around line 147 and the innermost handler around line 129. Reproduce the non-existent-record query on macOS, then trace how returned rrclass and rrtype are handled. Done means the query no longer waits about 30 seconds, follows a returned CNAME when appropriate, and reports an error otherwise.

Written by the indexing model from the issue text.