feat(upload): file upload endpoint

Adds an upload endpoint to our API. This has been implemented using
multer as a middleware for file validations and restrictions on file
size. Basic happy/unhappy flow tests pass.

Author: bitbeckers

package.json

@@ -63,6 +63,7 @@
     "kysely": "^0.27.4",
     "lodash": "^4.17.21",
     "lru-cache": "^11.0.0",
+    "multer": "1.4.5-lts.1",
     "node-cron": "^3.0.3",
     "pg": "^8.12.0",
     "reflect-metadata": "^0.2.2",
@@ -95,6 +96,7 @@
     "@swc/cli": "^0.3.12",
     "@swc/core": "^1.4.15",
     "@types/body-parser": "^1.19.5",
+    "@types/multer": "^1.4.12",
     "@types/node-cron": "^3.0.11",
     "@types/pg": "^8.11.6",
     "@types/sinon": "^17.0.2",