[#10238] Update front-end dependencies (#10247)

* Update Angular to 9 and most front-end dependencies

* Fix some Angular configuration

* Change TestBed.get to TestBed.inject

* Update forkJoin to use array instead of multiple arguments

* Remove static:false parameter for ViewChild

* Update Jest snapshots; remove ng-reflect

* Fix other build errors and warnings

* Expand stylelint to test inline styles in HTML files

* Add template type checks

* Fix some CI configurations

.travis.yml

@@ -1,4 +1,5 @@
 language: java
+os: linux
 dist: xenial
 jdk:
   - openjdk8

appveyor.yml

@@ -27,7 +27,7 @@ build_script:
   - gradlew.bat downloadLinters
   - gradlew.bat lint --continue
   - gradlew.bat componentTests
-  - npm install
+  - npm ci
   - npm run lint
   - gradlew.bat generateTypes
   - npm run coverage

docs/setting-up.md

@@ -45,10 +45,10 @@ These tools are necessary regardless of whether you are developing front-end or
 
 If you want to develop front-end, you need to install the following:
 
-1. Install Node.js (minimum version 8.9.4).
-1. (Optional but highly recommended) Install Angular CLI version 8 globally.
+1. Install Node.js (minimum version 12.11.1).
+1. (Optional but highly recommended) Install Angular CLI version 9 globally.
    ```sh
-   npm install -g @angular/cli@8
+   npm install -g @angular/cli@9
    ```
    **Verification:** Run `ng` and you should see a list of available Angular CLI commands.