Move plugins to express-twtkpr-core-plugins package

Add plugin structure
Fix stale cache after posting
Update to v0.9.0

src/middlewares/queryHandler/followingHandler.ts

@@ -19,7 +19,7 @@ import NodeCache from '@cacheable/node-cache';
 export default function followingHandler(
 	req: Request,
 	res: Response,
-	cache: NodeCache<unknown>,
+	following: Twttr[],
 	followingParameter: QueryParameters['following']
 ) {
 	const followingsToMatch = getQueryParameterArray(
@@ -40,7 +40,7 @@ export default function followingHandler(
 	if (wantsJson) res.set('content-type', 'application/json');
 	else res.set('content-type', 'text/plain');
 
-	const matchedFollowing = (cache.get('following') as Twttr[]).filter(
+	const matchedFollowing = following.filter(
 		({ nick, url }) =>
 			(!followingsToMatch.length ||
 				(followingsToMatch.length === 1 && followingsToMatch[0] === '') ||