feat(pricing, types, utils, medusa-sdk): Pricing Module Setup + Currency (#4860)

What:

- Setups the skeleton for pricing module
- Creates service/model/repository for currency model
- Setups types
- Setups DB
- Moved some utils to a common place

RESOLVES CORE-1477
RESOLVES CORE-1476

packages/pricing/src/models/currency.ts

@@ -0,0 +1,27 @@
+import { Entity, PrimaryKey, Property } from "@mikro-orm/core"
+
+@Entity({ tableName: "currency" })
+class Currency {
+  @PrimaryKey({ columnType: "text" })
+  code!: string
+
+  @Property({ columnType: "text" })
+  symbol: string
+
+  @Property({ columnType: "text" })
+  symbol_native: string
+
+  @Property({ columnType: "text" })
+  name: string
+
+  // @Property({ persist: false })
+  // get includes_tax() {
+  //   // TODO: This comes from a feature flag
+  //   // Figure out how we're handling FF in modules
+  //   // For now, returning default as true
+  //   // This should also not fall on the hands of the model
+  //   return true
+  // }
+}
+
+export default Currency

packages/pricing/src/models/index.ts

@@ -0,0 +1 @@
+export { default as Currency } from "./currency"