Replace ParameterControlHighlightInfo::parameterIndex With Parameter ID String

I’m sure this is on the ‘todo’… but the deprecation of the AudioProcessor methods that use parameter indices means that AudioProcessorEditor::setControlHighlight() must iterate over parameters, comparing AudioProcessorParameter::getParameterIndex() to find a match.

If the goal is to only access parameters via their ID strings, then the ParameterControlHighlightInfo struct needs to change to include the param ID instead of (or alongside, if also including the index is more helpful) the integer index. Then this can interface with AudioProcessorValueTreeState::getParameter().