Add allowAppDeployFailures boolean property

[brideck]

Short description of what this resolves:

The WebSocket TCK contains some negative deployment tests that attempt to deploy applications that are expected to fail, but then need to proceed into test methods in order to check that various endpoints have not been registered. Currently, these failing applications prevent Arquillian from creating a URL suitable for testing.

Changes proposed in this pull request:

• Create a new allowAppDeployFailures property that defaults to false, maintaining normal, expected behavior
• Setting this new property to true will ignore any deploy exceptions that occur while processing all applications. In the case of an ignored exception, the plugin will proceed to create a best guess URL for the application that Arquillian can use for testing.

Fixes: #137

[brideck]

Jared reminded me that I had originally proposed a different property name in the linked issue. We both like that name more than what I'd originally used here, so I've updated that and swizzled the implementation to more accurately match it.

[Azquelt]

I hate this, the TCK is broken, we can't be the only people hitting this.

I can't decide whether I think this hack is bad enough that we should instead subclass the container in the test runner and catch and swallow exception messages from the deploy method.

[brideck]

Still a hack, but we could more limit the scope by just skipping the exception particular to the case where apps haven't started.

https://github.com/OpenLiberty/liberty-arquillian/blob/main/liberty-managed/src/main/java/io/openliberty/arquillian/managed/WLPManagedContainer.java#L1280

[Azquelt]

I'm less fussed about exactly how we allow deployment to succeed when the app fails to start, and more about adding in an option that we'll have to support forever.

I don't object to the way you've implemented it, and if we really need this option, we can push ahead with it.