Refactor data handlers + misc fixes

This refactors the data handlers into a more standard/understood model-like architecture, to prepare for a new, more robust config system.

It also fixes a problem with creating new Notes and uploading new Photos via the web interface (related to #58).

Finally, it speeds up docker builds by sending in less files, which aren't necessary or will be built anyway.

This is all in preparation to allow building #13 more robustly.

lib/interfaces/database.ts

@@ -1,4 +1,4 @@
-import { Client } from 'https://deno.land/x/postgres@v0.19.2/mod.ts';
+import { Client } from 'https://deno.land/x/postgres@v0.19.3/mod.ts';
 import 'std/dotenv/load.ts';
 
 const POSTGRESQL_HOST = Deno.env.get('POSTGRESQL_HOST') || '';