Add QUERY caching support

[desiderantes]

Continuing the work from #8550, this PR adds logic for cache support on QUERY requests. I am a bit unsure on visibility for the new key method vs the old one, so I've left it unsolved. Also, on whether the cost of hashing the body would make it worth it (I guess some sort of warning should be added)

[yschimke]

./gradlew :spotlessApply to cleanup formatting issues

[yschimke]

Failing on existing tests

DnsOverHttpsTest > usesCacheOnlyIfFresh() FAILED
    java.net.UnknownHostException: google.com
        at okhttp3.dnsoverhttps.DnsOverHttps.throwBestFailure(DnsOverHttps.kt:163)
        at okhttp3.dnsoverhttps.DnsOverHttps.lookupHttps(DnsOverHttps.kt:87)
        at okhttp3.dnsoverhttps.DnsOverHttps.lookup(DnsOverHttps.kt:68)
        at okhttp3.dnsoverhttps.DnsOverHttpsTest.usesCacheOnlyIfFresh(DnsOverHttpsTest.kt:297)

        Caused by:
        java.io.IOException: canceled due to java.lang.IllegalArgumentException: method GET must not have a request body.
            at okhttp3.internal.connection.RealCall$AsyncCall.run(RealCall.kt:542)
            at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
            at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
            at java.base/java.lang.Thread.run(Thread.java:1583)

[yschimke]

@martinbonnin Do your worst!

[martinbonnin]

Do we need to store the request body in cache?

Looking at the code, it looks like storing a request in the cache is already destructive as only the vary headers of the request are stored (not all of them).

I think I wouldn't mind too much if Cache.Entry.body was missing and saving some bytes there.

[yschimke]

Storing a hash instead would seem a lot less disruptive to the format. Perhaps it could be stored as a synthetic header?

[martinbonnin]

Do we even need to store anything? What's the use case for reading that request body from the cache?

[yschimke]

True, it just needs to be part of the key. I think.

[yschimke]

If we can avoid changing the format, that would be good.

[yschimke]

Reverted

[yschimke]

@swankjesse can you take a look. We should land this before a new release.