Write a SpacetimeDB backend module in Rust that defines a table and these five empty reducers.

TABLES
- EmptyTable
  - Struct: EmptyTable
  - Fields:
    - id: i32 (primary key)

REDUCERS
- empty_reducer_no_args: no arguments, returns (), empty body
- empty_reducer_with_int: (count: i32), returns (), empty body
- empty_reducer_with_string: (name: String), returns (), empty body
- empty_reducer_with_two_args: (count: i32, name: String), returns (), empty body
- empty_reducer_with_three_args: (active: bool, ratio: f32, label: String), returns (), empty body