Adds pagination for custom props & fixes an issue with errant (none) return values

[Vigasaurus]

Changes

Fixes #1353 by adding a "Load More" button to the bottom of the custom props list
Potentially fixes #550 (but that may have already been fixed with the old way of limiting to 100)

Also fixes an issue where the (none) value for custom props was being returned at all times, meaning that if you requested 100 items, it would return those 100 items + the none entry if there were the full 100 items to be returned, meaning that in a paginated setup, the none entry would be in the first page & not in its correct sorted order. Fixes this by 1. not applying the limit nor the offset to the none entry query (since it's extra filtered and would always be returning one row) and 2. removing the none entry from the zipped results if it was the 101st (or rather, the entry with an index == limit) entry in the array (this implies that it was added where it was not yet necessary, and it should instead be returned on the next (or further) page.

Tests

• This PR does not require tests

Changelog

• Entry has been added to changelog

Documentation

• This change does not need a documentation update

[metmarkosaric]

This is great, thanks @Vigasaurus !

[ukutaht]

Looks god to me.

Historically I haven't been testing things thoroughly but I think we're at a point where the project is getting pretty big and complex and I want to rein things in a bit.

This can be tested in the breakdown_test.exs file because there you can specify a low value for limit so you don't have to create 100 DB entries just for testing.

[ukutaht]

Thanks!