Check over all custom rate limit records to ensure there are no duplicates

[GUI]

See #303 and #304. Since duplicate rate limit records defined on users may have unexpectedly popped up when making edits, and this then leads to unexpected behavior,we should check the records in our database to ensure nobody else has accidentally run into this and not noticed.

[GUI]

In fixing #306, I discovered that the root cause for these different rate limit bugs was a change I made that got rolled out during the larger Lua-ralated upgrades (#294). See NREL/api-umbrella@af74645 for more detail.

It's unfortunate we didn't catch this earlier, but this at least means it's only been broken since November, and not for forever as I was initially fearing (and also confused as to how we hadn't seen this before). This means that when we check for problematic records, we should only see possible issues in records modified after mid November. However, it's probably still worth checking everything while we're at it, just to be doubly sure.