mgr/dashboard: Enable compiler options used by Angular --strict flag
Recently Angular added a new flag to the "ng new" command, that adds 5 new typescript compiler options.
They add more strict rules that help the code to be more readable and less prone to errors.
The PR can be found here: https://github.com/angular/angular-cli/pull/14905
noImplicitAny - https://basarat.gitbooks.io/typescript/docs/options/noImplicitAny.html
noImplicitReturns - https://lucidchart.com/techblog/2018/06/20/how-to-actually-improve-type-safety-with-the-typescript-strict-flags/
noImplicitThis - https://logicbig.com/tutorials/misc/typescript/no-implicit-this.html
noFallthroughCasesInSwitch - https://typescriptlang.org/docs/handbook/release-notes/typescript-1-8.html
strictNullChecks - https://typescriptlang.org/docs/handbook/release-notes/typescript-2-0.html
I would suggest to postpone strictNullChecks until we start using TS 3.7, since it introduces Optional Chaining and Assertion Functions , and I think that would simplify a lot the code.