Migrate case-types from OptionGroup to new table

Case types are currently represented as OptionValues in an OptionGroup. We want create a new table, civicrm_case_type. This includes:

• Define schema
  table name: civicrm_case_type
  id int unsigned autoincrement
  name varchar (64)
  title varchar (64)
  description varchar (255)
  is_active boolean
  is_reserved boolean
  weight int (11)
  module_data longtext
  xml_definition blob

• Add SQL table
• Test install logic
• Add upgrade logic
• Triage anything which relies on the OptionGroup (ie identify them; fix where easy; make new tickets/prioritize where hard)