It appears that the intent is to return an unlisten function when `on` is called. The message bus implementations indicate that. However, the `MessageBus` abstract class returns `void` instead.
Change to `on: () => void`.
PR Close#62898
Enabling `strict` is part of an effort to improve the quality of the devtools code base.
One of the direct side effect is to enable `noImplicitAny`, `strictPropertyInitialization` and `strictBindCallApply`.
This commit also replaces `fullTemplateTypeCheck` with `stringTemplates`.
PR Close#53340
Previously the typescript override keyword was not on these methods. Now that devtools uses the tslint config in angular/angular (because of the no-implicit-override-abstract rule) we need to add these key words explicitly to method overrides. That is what this commit does.
This commit runs tslint --fix with the angular/angular tslint configuration on the files inside the devtools codebase.
Notably, the file-header rule in `tslint.json` was missing a default attribute. This commit adds that default attribute and sets it to the
license header that is present in all files in this repo. After running tslint --fix with this default added, this commit added the license header to all files in the devtools directory. Note for the reviewer: the automatically added license headers were added as comments with the "/*!" prefix. Since we want these comments removed in builds, and the rest of the codebase uses "/**", a simple find and replace was performed on the devtools directory to change these prefixes to "/**".
Formats the entire devtools directory with the ng-dev formatting tool. Previously we relied on prettier, so this commit also remove prettier from devtools' dependencies.
