Remove package same-origin with new method in misc

[molant]

We are using the package same-origin somewhere in the code. It's a bit outdated and the new WHATWG URL parser available in node 8 makes things a lot easier to verify if two urls have the same origin.

We need to:

1. Create a new method under utils/misc: sameOrigin with something similar to the following:

export const sameOrigin(url1: string, url2: string): boolean {
  return (new URL(url1)).origin === (new URL(url2)).origin;
}

2. Remove same-origin from the dependencies and use this method.

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