Include senior and regional delegates in the results email thread

[mirandapedro]

Currently, senior and regional delegates are not included in the thread that is created with the competition delegates and the WRT after the results of a competition are posted.

It'd be a good idea to have senior and regional delegates included in the thread to allow them to:

• support their region's delegates whenever needed, e.g. navigating a request from the WRT
• assess the delegates' performance when posting results, which is important when thinking about promotions
• make sure their region's delegates follow up with results change requests, e.g. after a WRC decision