normalize "text" columns into own table by default, to make property indexable

[uladkasach]

https://stackoverflow.com/questions/1827063/mysql-error-key-specification-without-a-key-length

e.g., the following definition is not ideal

export const description = new Entity({
  // really this is a value object - but we're just not unique on the 'content' column because we cant stick it in an index
  name: 'description',
  properties: {
    content: prop.TEXT(),
    hash: prop.CHAR(64), // hash of the description, since we cant index on TEXT type
  },
  unique: ['hash'],
});

[uladkasach]

todo: check if this is relevant with postgres still