feat: excel import (#527)

* refactor: simplify excel import

* chore: add external deepmerge utility

* chore: create import map utilities

* chore: increase size limits on uploads

* style: small presentation tweaks

* feat: resolve times on excel import, refs #508

apps/client/src/theme/OntimeProgress.ts

@@ -0,0 +1,8 @@
+export const ontimeProgressGray = {
+  track: {
+    background: '#f6f6f6', // $gray-500
+  },
+  filledTrack: {
+    background: '#578AF4', // $blue-500
+  },
+};