Generalize "samplesheet" and sample_data

[Adam]

There is the possibilities that instead of samples, there are libraries, pools, or other. Basically, generalize it into "tabular data".

• Make it possible to have multiple schemas.
• Have each schema generate a tab in the submission data table dialog. So it may have "Pools" and "Libraries" as an example.
• Make the different types configurable in the site settings. So something like:
  SUBMISSION_TABLE_TYPES = [{'id':'pools', 'name': 'Pools', 'description': '....', 'key': 'pool_id'}, ...]
  The ids will be useful for determining how to store and treat the submission data (such as creating database records in Sample table, etc)
• Make it possible to join tables on key (pool_id) in order to make relations in database, as well as validate.