Only include detailed HTTP diagnostics in node health output when --verbose is set

[nblumhardt]

No --verbose flag - parseable JSON:

> seqcli -- node health
{"status":"The Seq node is in service."}

With the flag (similar output to today):

> seqcli node health --verbose
HTTP 1.1 200 OK
Date: Mon, 08 Jul 2024 04:16:13 GMT
Transfer-Encoding: chunked
Connection: keep-alive
Vary: Accept-Encoding
...
{"status":"The Seq node is in service."}

No --json flag is currently required - the output is always the literal response from the server, for easy diagnostics (e.g. when the actual response is some random HTML page from a proxy/gateway). Could reevaluate this down the track.

[KodrAus]

RUNNING NodeHealthTestCase                                
{"status": "The Seq node is in service."}
FAIL
Xunit.Sdk.StartsWithException: Assert.StartsWith() Failure: String start does not match
String:         "{"status": "The Seq node is in service."}"···
Expected start: "HTTP 1.1 200 OK"
   at Xunit.Assert.StartsWith(String expectedStartString, String actualString, StringComparison comparisonType) in /_/src/xunit.assert/Asserts/StringAsserts.cs:line 899
   at Xunit.Assert.StartsWith(String expectedStartString, String actualString) in /_/src/xunit.assert/Asserts/StringAsserts.cs:line 879
   at SeqCli.EndToEnd.Node.NodeHealthTestCase.ExecuteAsync(SeqConnection connection, ILogger logger, CliCommandRunner runner) in /home/appveyor/projects/seqcli/test/SeqCli.EndToEnd/Node/NodeHealthTestCase.cs:line 16
   at SeqCli.EndToEnd.Support.IsolatedTestCase.ExecuteTestCaseAsync() in /home/appveyor/projects/seqcli/test/SeqCli.EndToEnd/Support/IsolatedTestCase.cs:line 66
   at SeqCli.EndToEnd.Support.TestDriver.Run() in /home/appveyor/projects/seqcli/test/SeqCli.EndToEnd/Support/TestDriver.cs:line 52