SOLR-9280 - make nodeName a configurable parameter in solr.xml

[kelaban]

This patch makes live nodeName configurable via solr.xml by setting

<solr>
    <solrcloud>
        <str name="nodeName">${solr.nodeName:}</str>
    </solrcloud> 
</solr>

To test, I randomly set nodeName in AbstractFullDistribZkTestBase for complete coverage.

I've gotten all tests to pass both when ALWAYS using a random nodeName and with it being set randomly. However during one particular run I got a test failure for the following:
ant test -Dtestcase=TestReqParamsAPI -Dtests.method=test -Dtests.seed=391BC4715DE8C2FE -Dtests.slow=true -Dtests.locale=pl-PL -Dtests.timezone=Asia/Chungking -Dtests.asserts=true -Dtests.file.encoding=UTF-8 but am unable to reproduce the issue in eclipse and at this time am not sure if its related

[kelaban]

Randomly setting nodeName in tests which extend from AbstractFullDistribZkTestBase hits about 60 solr cloud tests. But there are also about 30 other cloud tests which use MiniSolrCloudCluster which will not get this randomness applied. To increase coverage we can add randomness into this class as well.

[kelaban]

Updated so the patch now applies cleanly. I've been having trouble getting tests to pass on vanilla master branch, so I cannot tell if this is causing any to fail. I've spot checked a few tests with this patch and they worked fine

[kelaban]

Additionally work for SOLR-9281 is being done here (https://github.com/kelaban/lucene-solr/tree/jira/master/SOLR-9281) but will hold out on a PR as it relies on this branch