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/profile/bdAddress.fsh

@@ -1,7 +1,7 @@
 // @Name: Profile
-// @Description: Example of a profile of the Patient resource. This example includes a few of the most commonly used constraints and documentation features of FHIR profiles.
+// @Description: Example of a profile of the Address resource for Bangladesh.
 
-Profile:     bdAddress
+Profile:     BDAddress
 Id:             bd-address
 Parent:      Address
 Title:         "Address for Bangladesh"
@@ -9,4 +9,9 @@ Description: "Address for Bangladesh Standard"
 
 
 * country 1..1 MS
-* extension contains Division named division 1..1 MS
+* extension contains Division named division 1..1 MS
+
+* district 1..1 MS
+* district from BDDistrictsVS
+
+* extension contains Upazillas named upazilla 1..1 MS