Fix sonar issues

Author: francisco-videira-nhs

lambdas/api-handler/src/handlers/patch-letter.ts

@@ -32,7 +32,7 @@ export const patchLetter: APIGatewayProxyHandler = async (event) => {
       else throw error;
     }
 
-    const result = await patchLetterStatus(mapToLetterDto(patchLetterRequest, supplierId!), letterId!, letterRepo);
+    const result = await patchLetterStatus(mapToLetterDto(patchLetterRequest, supplierId), letterId, letterRepo);
 
     return {
       statusCode: 200,

lambdas/api-handler/src/mappers/letter-mapper.ts

@@ -1,5 +1,5 @@
 import { LetterBase, LetterStatus } from "../../../../internal/datastore";
-import { GetLettersResponse, GetLettersResponseSchema, LetterDto, LetterStatusSchema, PatchLetterRequest, PatchLetterResponse, PatchLetterResponseSchema } from '../contracts/letters';
+import { GetLettersResponse, GetLettersResponseSchema, LetterDto, PatchLetterRequest, PatchLetterResponse, PatchLetterResponseSchema } from '../contracts/letters';
 
 export function mapToLetterDto(request: PatchLetterRequest, supplierId: string) : LetterDto {
   return  {

lambdas/api-handler/src/services/letter-operations.ts

@@ -1,4 +1,4 @@
-import { Letter, LetterBase, LetterRepository } from '../../../../internal/datastore/src'
+import { LetterBase, LetterRepository } from '../../../../internal/datastore/src'
 import { NotFoundError, ValidationError } from '../errors';
 import { LetterDto, PatchLetterResponse } from '../contracts/letters';
 import { mapToPatchLetterResponse } from '../mappers/letter-mapper';