Give 'this' keyword suggestion the same `sortText` as class properties if inside a class

From https://github.com/Microsoft/vscode/issues/66868 <!-- Please try to reproduce the issue with `typescript@next`. It may have already been fixed. --> **TypeScript Version:** 3.4.0-dev.20190220 <!-- Search terms you tried before logging this (so others can find this issue more easily) --> **Search Terms:** - suggestions - completions - sortText **Code** For the javascript: ```js class Foo { constructor() { this.prop = 1; } render() { th } } ``` * Trigger intellisense after `th` in `render` **Expected behavior:** `this` should be the first suggestion in VS Code **Actual behavior:** `render` and then `prop` are the first suggestions The root cause of this is that the suggestion for `this` has a `sortText` of `"0"` while the one for `prop` and `render` have a `sortText` of `"1"`. This causes VS Code to sort `prop` and `render` before `this` @amcasey @minestarks I'm not sure if the current sorting issue would also effect VS **Playground Link:** <!-- A link to a TypeScript Playground "Share" link which demonstrates this behavior --> **Related Issues:** <!-- Did you find other bugs that looked similar? -->