Small collection of UI nits

[ShadowJonathan]

• in-reply-to's look out-of-place
  
  (Further improve replies matrix-org/matrix-react-sdk#6396 should be noted here)

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• Single emoji padding is a bit off on the bottom
  
  (In general, i think removing a message bubble around emojis entirely could be an alternative, see Move emoji-only messages out of bubbles SchildiChat/schildichat-desktop#37)

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• Long URL preview text overflows out of the message
  

[robintown]

Closing this since the first 2 issues are now fixed