Raw block bug fix

Removal of raw block causes issues so in the create/update actions, I iterated over ContentBlocks and if "raw" didn't exist, I would insert it. Also removed the delete button if ContentBlock type was 'raw'. 
While this works, you are going to re-run this for every content_block, which is unnecessary.  I think you should just do a custom validate method
```
validate :raw_content_block_exists

def raw_content_block_exists
unless content_blocks.where(type: 'raw').any?
errors.add(:base, "Raw block is required")
end
end
```