refactor(NODE-7313): only use dns.resolve for all types

[durran]

Description

Refactors all dns resolution to only go through lookup and resolve.

Summary of Changes

• Refactors dns resolution to only use lookup and resolves
• Fixes all tests

What is the motivation for this change?

NODE-7313

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• Lint is passing (npm run check:lint)
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[baileympearson]

Can we choose an approach that doesn't necessitate casting? One approach would be something like:

Suggested change

	return async function dnsReqRetryTimeout(lookupAddress: string) {
	try {
	return await dns.promises[api](lookupAddress);
	return (await dns.promises.resolve(lookupAddress, rrtype)) as dns.SrvRecord[] | string[][];
	} catch (firstDNSError) {
	if (firstDNSError.code === dns.TIMEOUT) {
	return await dns.promises[api](lookupAddress);
	return (await dns.promises.resolve(lookupAddress, rrtype)) as dns.SrvRecord[] | string[][];
	} else {
	throw firstDNSError;
	}
	}
	};
	}
	const resolve =
	rrtype === 'SRV'
	? (address: string) => dns.promises.resolve(address, 'SRV')
	: (address: string) => dns.promises.resolve(address, 'TXT');
	return async function dnsReqRetryTimeout(lookupAddress: string) {
	try {
	return await resolve(lookupAddress);
	} catch (firstDNSError) {
	if (firstDNSError.code === dns.TIMEOUT) {
	return await resolve(lookupAddress);
	} else {
	throw firstDNSError;
	}
	}
	};

Another would be modifying the function to instead accept a lookup function, which it then calls.