fix(utils): bignumber util considers nullable options when setting value (#6499)

what:

- when setting null for nullable columns, big number utils should not throw error
- remove circular soft delete depenedencies for cart module
- trims zeros on big number values

.changeset/itchy-bags-play.md

@@ -0,0 +1,5 @@
+---
+"@medusajs/utils": patch
+---
+
+fix(utils): bignumber util considers nullable options when setting value