Add `origin` property to MessageSender

[amakhrov]

Community guidelines:

• [x] I have read and understand the contributing guidelines and code of conduct

This PR contains:

• [ ] bugfix
• [ ] feature
• [ ] refactor
• [ ] documentation
• [x] other

Are tests included?

• [ ] yes (bugfixes and features will not be merged without tests)
• [x] no

Breaking Changes?

• [ ] yes (breaking changes will not be merged unless absolutely necessary)
• [x] no

List any relevant issue numbers:

Description

Copied over from @types/chrome: https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/chrome/index.d.ts#L6943-L6947

Related documentation: https://developer.chrome.com/docs/extensions/reference/runtime/#type-MessageSender