Move line symbol state to database

[davenquinn]

Fault symbol label state (e.g., whether a map has trustworthy symbol label orientations, and the direction of these labels) is currently stored in frontend code but this needs to be moved to the database.

We need

• a database field to store whether lines are oriented for a given map
• tile data field to store whether any given line is oriented (and thus can receive a symbol label)