[Streaming] Fix issues when not using try-with-resource

[newtork]

Make the streaming API lenient towards try-with-resources.

Before:

• with try-with-resource: HTTP connections are closed in normal cases, response errors, http errors
• without try-with-resource: HTTP connections are NOT closed

After:

• with try-with-resource: HTTP connections are closed in normal cases, response errors, http errors
• without try-with-resource: HTTP connections are closed in normal cases, and http errors. Errors in response payload does not lead to closing of HTTP connection.

- InputStream <> BufferedReader <> Stream
+ InputStream <> BufferedReader <> [HandledIterator] <> Stream

The suggested HandledIterator understands when BufferedReader#readLine() returns null, then the underlying InputStream shall be closed [left]. Also when the consuming Stream is closed or finished iteration [right].

See JavaDoc of String BufferedReader#readLine() to understand null contract.

See JavaDoc and code of Stream BufferedReader#lines() for comparison.

[CharlesDuboisSAP]

You can remove try-with-resources in the controller and readme since it doesn't do anything anymore

The close handler is still there

[MatKuhr]

Left some comments. I would consider un-nesting the HandledIterator and merge it with the StreamConverter into just one class.

[CharlesDuboisSAP]

I get a timeout on http://localhost:8080/streamChatCompletionDeltas

[CharlesDuboisSAP]

Suggested change

	assertThatCode(sut::count)
	assertThatThrownBy(sut::count)

The main difference with assertThatCode(ThrowingCallable) is that this method fails if no exception was thrown.

[CharlesDuboisSAP]

Suggested change

	import static org.assertj.core.api.Assertions.assertThatCode;
	import static org.assertj.core.api.Assertions.assertThatThrownBy;

[CharlesDuboisSAP]

The stream is closed by the user of the Stream

This is false now. Could you update this comment and duplicate it in IterableStreamConverter.lines()
Alternatively just merge parseResponse inside of handleResponse since parseResponse only contains a return and nothing else

[CharlesDuboisSAP]

What can be thrown here?