Migrate eg2 from TSLint to ESLint

I ran through the generator steps here, as well as `ng lint --fix` to apply some fixes: user/sandbergja/lp1959048_eslint

To try it out on an existing installation, you'll just want to run npm install to install the dependencies.

It is a bit pickier than the old linter, for better or worse. It does look for objectionable bits in the HTML templates as well as the ts files, which seems like a nice improvement. However, there are 121 errors that the new linter picked up that it couldn't fix automatically. :-(

I took a look at this today and reviewed the classes of errors that ng lint --fix couldn't deal with.

These two classes look straightforward to deal with, just a little time-consuming:

     84 @angular-eslint/no-empty-lifecycle-method
    130 @angular-eslint/template/eqeqeq

However, I think these need a little thought:

     44 @angular-eslint/no-output-on-prefix

This is coming from the Angular style guide, specifically https://angular.io/guide/styleguide#dont-prefix-output-properties, which doesn't mention any particular risk of bugs by having output properties named on*.

For the sake of both time and reducing rework of pending pull requests that use core eg components, I suggest that

* this check be turned off where present for components under src/app/share, then slated for cleanup on a component-by-component basis while avoiding forcing much churn on pending pull requests
* fixed for components elsewhere, as those typically will have only one or two consumers each

I do think that we should not add any further on* output properties, so I'm not advocating for turning off this check for the entire project.

I've rebased my branch and done the manual lint fixes per Galen's suggestions: user/sandbergja/lp1959048_eslint

Tested! I've pushed a signoff branch to user/gmcharlt/lp1959048_signoff; this branch also includes a release notes entry.

Thanks, Galen! I confirmed with Bill that this won't interfere with the patron angular work. Pushed to master.