Add star related boolean columns

This is a breaking change in how we display card information related to special abilities.

I'm adding 9 new _star boolean columns to capture if there should be a star related to a specific card attribute. These columns just indicate whether a star should be displayed but it doesn't include the text for the special ability. I'm removing 4 _text string columns since we should just be using the text column directly for any card text to simplify things. The combination of using text and these new _star columns should allow us to display the correct text for each card and indicate whether the attack/thwart/etc has a special ability associated with it.

-- New columns added
ALTER TABLE card
  ADD attack_star TINYINT(1) DEFAULT NULL,
  ADD thwart_star TINYINT(1) DEFAULT NULL,
  ADD defense_star TINYINT(1) DEFAULT NULL,
  ADD health_star TINYINT(1) DEFAULT NULL,
  ADD recover_star TINYINT(1) DEFAULT NULL,
  ADD scheme_star TINYINT(1) DEFAULT NULL,
  ADD boost_star TINYINT(1) DEFAULT NULL,
  ADD threat_star TINYINT(1) DEFAULT NULL,
  ADD escalation_threat_star TINYINT(1) DEFAULT NULL;

-- Old columns deleted
ALTER TABLE card
  DROP boost_text,
  DROP real_boost_text,
  DROP scheme_text,
  DROP attack_text;

I'll be making additional PRs in the JSON repo to update cards to use these new _star columns and stop using the existing _text columns.

Other fixes:

I updated the star icon class to be .icon-star to match the [star] keyword used to replace text with icons
If an integer is null, it should show up as an em dash instead of an en dash. Hulk ally's thwart is an example.

zzorba / marvelsdb

Add star related boolean columns #221