feat: make spatial entry optional and authoritative

frontend/src/types.ts

@@ -76,6 +76,19 @@ export interface AreaListResponse {
   offset: number
 }
 
+export interface MunicipalitySearchItem {
+  niscode: string
+  name: string
+  name_nl?: string | null
+  name_fr?: string | null
+  name_de?: string | null
+}
+
+export interface MunicipalitySearchResponse {
+  items: MunicipalitySearchItem[]
+  total: number
+}
+
 export interface DatasetCreateResponse {
   id: string
   name: string