WCA Live Integration Pre Work #2: Add liveResult and liveAttempt models

[FinnIckler]

Also confirmed working using my test page.
wca live's result table additionally has

      t.integer :ranking
      t.integer :best, null: false
      t.integer :average, null: false
      t.string :single_record_tag, limit: 255
      t.string :average_record_tag, limit: 255
      t.boolean :advancing, default: false, null: false
      t.boolean :advancing_questionable, default: false, null: false

But I am not sure which one of these we should also use and which one we should just compute on the fly.

[FinnIckler]

I've added the factories and some basic tests. There will be a ton more when validating cutoffs and time limits will be introduced in a future pr