Feature: allow the bot to be configured "extra SFW"

[ghost]

Feature

Add functionality so that OwO can be configured to be extra SFW, i.e., preventing GIFs or text from being selected which are even slightly suggestive.

Reasoning

OwO bot has many fun features with broad appeal, including to servers which may have high populations of asexual (ace) people, those who feel anxiety when unexpectedly exposed to suggestive content, or both.

Possible implementations

1. A general setting that removes specific GIFs/text from the possible results, the list of which is curated by the OwO team
2. Granular settings that allow server owners to specify which GIF/text results they do not want to be randomly selected on the server