Disable metapaths with path count too high

[vincerubinetti]

As discussed here, querying for the list of paths for a metapath that has a very large number of paths (say 100,000) tends to crash the database and not return a result. Therefore, it seems like we'll have to limit which metapaths can be checked.

The tentative limit discussed is 10,000 paths. Any metapath with more than that many paths should be disabled from being checked, or should at least show a warning next to it.

[vincerubinetti]

I think we don't necessarily have to do this anymore, since this frontend is more robust and can't hang/crash as easily. The worst that happens is that the paths simply don't show up in the paths table (but the metapath stays checked).

If we were to do it though, I think the limit could be 100,000. I'm now fairly easily able to query paths < 100,000: