Re-enable strict mode (#1749)

## Description:

Re-enable strict mode

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

Dockerfile

@@ -46,7 +46,7 @@ ENV NPM_CONFIG_IGNORE_SCRIPTS=1
 # Copy package.json and package-lock.json
 COPY package*.json ./
 # Install dependencies
-RUN npm ci --omit=dev
+RUN npm ci
 
 # Final image
 FROM base

tsconfig.json

@@ -21,7 +21,8 @@
     "resolveJsonModule": true,
     "strictNullChecks": true,
     "useDefineForClassFields": false,
-    "strictPropertyInitialization": false
+    "strictPropertyInitialization": false,
+    "strict": true
   },
   "include": [
     "src/**/*",