Memory provider bugs

[Akrion]

Few things I noticed when trying to play with the memory provider.

• [x] Facet type exclude filter option does not work
• [x] Exists type does not work on the initial load. Have to set a value and reset to the value you want for it to work.
• [ ] Add Custom Filter button shows on the filters side when there are no filters not already used. It should not show when all filters have been already used.
• [x] Date type
  • [x] The rolling option does not work
  • [x] The whole thing does not work with string dates. Have to convert the date to ms with getTime()

These might also be issues with the provider itself. Opening it here to start keeping track.

[daedalus28]

I think these are all memory provider issues, except perhaps Exists. I'm moving this issue to that repo.

[stellarhoof]

All these items have been addressed.