Changes

SPIGOT-6304: Removed the detection of legacy text based on color codes

Apparently there are items and plugins out there that still use legacy
color codes within text components, and which thereby break this
heuristic.

Our remaining approach to differentiate between legacy (plain) and
modern (JSON-based) text is to check if a particular text can be parsed
as JSON-based text. This approach is not perfect either as there are
ambiguous cases that it cannot resolve correctly. However, these cases
are hopefully rare enough in practice that this approach remains
suitable.