Support AMD imports with baseUrl and without paths in ts config

[eprincev-egor]

for example i have ts config:

{"compilerOptions": {
  "baseUrl": "./src"
}}

and have two source files

// pages/MainPage.ts
import {Grid} from "core/Grid";

// core/Grid.ts
export class Grid {}

i need to resolve import path in pages/MainPage.ts
from "core/Grid" to "../core/Grid"
because i have baseUrl in ts config and typescript understand types by path "core/Grid"