Renaming a Flex Bucket leads to confusion

[dkapell]

If a flex bucket is renamed, it keeps the flex bucket nature, but looks like a regular bucket, which leads to weird behaviours. We should:

1. add a visual indicator to flex buckets in the bucket editor, and to flex buckets that have a different name than flex on the schedule and game page slot indicators/widgets and/or
2. disable editing flex bucket name/description. I'm not sure there's a good reason to let a GM rename the flex bucket, when the name is what people know to look for for the flex behavior