Aggresively cache autocomplete results

[geoversed]

Is your feature request related to a problem?

The autocomplete function gets called every single time they type a letter, so if you query the database every time, it'll get pretty slow.

Describe the solution you'd like

You'll want to aggressively cache results so you don't have to query every single time.

We want to cache the following types of autocomplete results:

• [x] Item names (not for owned autocomplete)
• [x] Kona tags
• [ ] User Settings
• [ ] Guild Settings (when they arrive)

These data stored which is acquired via autocomplete generally speaking will never change at run time. Thus, these are going to be cached.

Additional Context

There are only 2 big problems in computer science: cache validation and naming things.

[geoversed]

Serving cached tag autocomplete results is probably not a good idea due to how quickly tags can be added/changed/removed. Other bots that have this feature also do not cache their results, so tag autocomplete results will most likely keep being fetched from the database.

Item autocomplete results will definitely be cached however.

[geoversed]

I'm considering also caching the results of kona tags, if it is feasible. These typically do not get deleted/created, so it is better to cache the results of these. Seems ideal to use LRU cache for all autocomplete results.

[geoversed]

Settings will be cached later when they are actually implemented