racing.proto:
• Added optional string parameter `order_by` as per Google design spec[1].
races.go:
• Changed `List` funct to accept ListRacesRequest param - this is required for accessing parameters outside of the filter.
• Added function `applyOrdering` which appends ORDER BY statement. By default it orders by `advertised_start_time` but also allows for custom ordering.
• Added function `toOrderBySql` which converts unvalidated external input for order by query and converts to a safe SQL format.

Correct out-of-date naming for RacesRepo interface List function.

• Update order by comment to describe usage.

• Added order by name test.

• Expanded order by test case to ensure that multi space, multi fied sorting is obeyed.

• Added line for order by parameter detailing its purpose.

• Fixed invalid testType of "db" for races_test.

• Fixed failing test cases due to compilation error with Init change.
• Fixed database in use error due to test case access other test cases databases.