Refactor Bangladesh Address Code Systems and Profiles

- Deleted the bdAddressCS code system file as it was no longer needed.
- Updated the division extension to accept string values instead of CodeableConcept.
- Created a new extension for Upazillas to standardize their representation in addresses.
- Modified the patient profile to include address constraints specific to Bangladesh, including the new Upazilla extension and district value set.
- Renamed the bdAddress profile to BDAddress for consistency and clarity.

input/fsh/extensions/upazilla.fsh

@@ -0,0 +1,10 @@
+
+Extension: Upazillas
+Id: bd-upazillas
+Title: "Upazilla"
+Description: "BD Upazilla"
+Context: Address
+
+
+* value[x] only string
+* value[x] from BDUpazillasVS