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

packages/utils/src/externals/deepmerge.ts

@@ -0,0 +1,2 @@
+// evaluating the library, we re-export to make it easy to detach
+export { deepmerge } from 'deepmerge-ts';