Implement richer support for multi tenancy

[Martinsos]

While you can implement multi tenant app right now, one thing we don't support is having a database per each tenant (e.g. organization), while still all being served by one Wasp app.

It would be interesting to learn more about what is expected from "multi tenancy" and see if we can provide deeper support for that.

Good model is likely Larevel with the Tenancy package: https://medium.com/@yaghi.moh/creating-multi-tenant-applications-with-laravel-5e02b42bbdf7 .

Related discord convo: https://discord.com/channels/686873244791210014/1245951215192375417/1246352304815214592

[chakravarthi-bb]

These are the features I am looking for

Serve multiple customers across different subdomains/custom domains with a single unified codebase
Multiple Databases approach might be overkill, I am ok with single database shared schema or single database with single schema
Fix Auth based on Server URL, as different custom domains will enable different logins and each sub domain should be redirected to the sub domain instead of main domain
I will keep on adding more to this list