Add proprietary/public to query/filters

[stscijgbot-jwql]

Issue JWQL-213 was created on JIRA by Bryan Hilbert:

From the JWQL survey:

Be able to query by whether data is proprietary or not. This would be very helpful in cases when using JWQL to find data for e.g. tutorials, presentations, etc.

We have this information, based on where the data reside in the filesystem. However, the data do move when they become public. We would need to make sure that JWQL sees this change.