Use tables for repeated bill information

[JustZack]

I.E. create a subjects table which has an id and text so that billsubjects simply has an id for the subject is references.

This essentially exists for the congresses table already, because the congress column implictly maps to congress text.

Apply this logic anywhere that it would be beneficial.
Possibly in:

• Related Bills, the reason & identifier column
• Bill Actions, the actionType column
• Text Versions, the versionType column
• Bill Committees, the action column
• Maybe for committees aswell, instead of using thomasId as a key
• ALL Bill tables, the type column (in related bills, relatedType too) - This one might be rather involved to fix

Goal is to:

1. Avoid data duplication
2. Have tables the frontend can easily use to present data filtering options