Honour ignoreOutsideDomain when set on its own in HostURLFilter

[rzo1]

HostURLFilter.configure() read the ignoreOutsideDomain parameter but tested the ignoreOutsideHost node for null. A configuration naming only ignoreOutsideDomain was silently discarded and the filter let every URL through; one naming only ignoreOutsideHost threw a NullPointerException at topology startup. Each parameter is now tested on its own.

Topologies setting only ignoreOutsideDomain will start restricting outlinks to the source domain, as configured. Configurations setting both keys, including all three archetypes, are unaffected.

For all changes

• Is there a issue associated with this PR? Is it referenced in the commit message? - no issue

• Does your PR title start with #XXXX where XXXX is the issue number you are trying to resolve? - no issue

• Has your PR been rebased against the latest commit within the target branch (typically main)?

• Is your initial contribution a single, squashed commit?

• Is the code properly formatted with mvn git-code-format:format-code -Dgcf.globPattern="**/*" -Dskip.format.code=false?

For code changes

• Have you ensured that the full suite of tests is executed via mvn clean verify? - core module tests only (348 run, all green)
• Have you written or updated unit tests to verify your changes? - two new cases in HostURLFilterTest, both fail without the fix
• If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under ASF 2.0? - no new dependencies
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