[FEATURE] More powerful user search

[JakubKoralewski]

Currently user search is done solely on an insensitive Prisma contains query (I think this uses LIKE under the hood):

lets-watch-it-together/src/pages/api/search/users.ts

Lines 27 to 31 in 2cf3b9a

	const users = await prisma.user.findMany({
	where: {
	name: { contains: query, mode: 'insensitive' },
	AND: { id: { not: { equals: session.user['id'] } } }
	},

We could investigate using:

• a search engine
  • elastic search
  • tantivy
• Postgres Full Text Search
• RediSearch

All of these may be impossible using Heroku's free tier's limits.