chore(ci): add dependency checks and reorganize tangled dependencies

This adds a dep check using `knip`. We use `depcheck` in Compass but this is deprecated and knip is recommend instead. This adds a basic configuration and then uses it to untangle some of our dependencies. This includes:

- Moving dependencies into dev dependencies, most notably `mongodb`! which we actually only use for types in the code itself at the moment.
- Moving certain types, consts into helper utils as they are only relevant there.

This seems like a useful feature and allows us to avoid mixing up our scripting or testing code with production.

Author: gagik

knip.json

@@ -0,0 +1,11 @@
+{
+  "entry": [
+    "src/index.ts!",
+    "src/lib.ts!",
+    "tests/**/*.ts",
+    "scripts/**/*.ts",
+    "eslint-rules/*.js"
+  ],
+  "ignore": ["tests/integration/fixtures/curl.mjs", "tests/vitest.d.ts"],
+  "ignoreExportsUsedInFile": true
+}