feat: Create `TCATextView`

[RemiBardon]

From #78

• Configurable to a certain degree visually and functionally
  • [x] Visually: Things like corner radius, the focus ring, etc.
  • [x] Functionally: Maximum number of lines (before it scrolls vertically)
  • [ ] Un-hardcode this value
• [x] Can show a placeholder
• [x] Sends text and selection changes to the ViewStore
• [x] Receives text and selection changes from the ViewStore
• [x] Its state might offer convenience methods to query the current selected word
• [ ] Selects the next responder when Tab is pressed
• [x] Does not know anything about tokens it only deals with an (NS)AttributedString and a NSRange.
• [x] Can detect keyboard events like mouse up, mouse down and other shortcuts used for keyboard navigation