MCR-3645 Refactor Solr Integration to Use Configurable Class Instance…

[sebhofmann]

Link to jira.

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[toKrause]

Properties containing comma-separated lists of values should be split with MCRConfiguration2::splitValue for consistent edge-case-behavior.

... or wait for #2855 and use @MCRPropertyList to inject List<String>-values.

Same for zkUrls and solrUls in MCRConfigurableSolrCloudCollection.ConfigAdapter and probably others.

[sebhofmann]

Fixed that.