IgnoreLargeDocumentsProcessorFactory should have a "permissive" mode

IgnoreLargeDocumentProcessorFactory only has a single way to handle documents that exceed its configurable size limit. The first violation throws a SolrException: in effect, short-circuiting any remaining documents in the "batch" and returning a 400 to the user.

This is great for end users whose clients are built to handle the resulting 400 response, and who can modify and resubmit the batch. But it's not ideal for every use-case, especially where "best-effort" indexing is good enough.

This ticket proposes adding a new "permissive" mode of handling too-large documents to ILDPF. Under this new mode "too-large" documents will be logged (and not indexed), but won't cause the entire batch to be aborted/error-out.