Religious units: Add number of remaining actions to icon

[JHCD]

Add the number of remaind actions (Spread Religion and Remove Heresy) for religious units like for workers.

[chaorace]

It might be tough to include multiple items to that element because it's only really supposed to hold a single character. Though, I feel that remaining actions is a more appropriate thing to display as opposed to the religious level of that unit, which is relevant considerably less often