Attempt to close all delegate readers even when some fail

[elimelec]

Motivation:

When a delegate reader fails during close(), the original implementation would stop immediately, preventing other delegates from completing their cleanup.

Similar to #4750

[elimelec]

@fmbenhassine This is split into 2 commits:

• One for CompositeItemReader
• One for CompositeItemStream

I think this PR (and also the previous one: #4750) may change the public API. I realized only now because some tests were failing because of the changes from CompositeItemStream. Also, the documentation was explicit that the close method is not fully cleaning all delegates.

I still left both changes since the interfaces is defined with throws ItemStreamException and I am not changing that part.

Let me know if I should change something.

[fmbenhassine]

Thank you for this second PR! Appreciated 👍

I see no public API changes, but I agree there is a small behavioral change in the sense that the exception is now suppressed instead of being the main one. Since we are fixing the partial cleanup bug, I believe this is acceptable for a patch release as long as we document the change about the way the exception is thrown (which is missing by now, but I will take care of that).

The PR LGTM, I will plan it for 5.2.2.

[fmbenhassine]

Rebased and merged, thank you for your contributions!

As mentioned previously, I updated the javadocs about the change in suppressed exceptions: 75edb29.