Add "exports" to get rid of "dist" from import paths

[sla100]

Is your feature request related to a problem? Please describe.
I'm always frustrated when I see the technical path dist while importing:

import "@ui5/webcomponents/dist/Button";

Describe the solution you'd like

Use exports package.json feature recognizable to modern tools (Node 12, Webpack 5)

"exports": {
  "./*": "./dist/*",
  "./package.json": "./package.json"
}

Additional context
Oldest tools may still use longest patch.