Removed `manual_blocks_enabled` flag.
Added a new `debug` flag:
```rust
    /// Should be used for local development only. Enabling debug mode:
    /// - Allows GraphQL Endpoints to arbitrarily advanced blocks.
    /// - Enabled debugger GraphQL Endpoints.
    /// - Allows setting `utxo_validation` to `false`.
    #[arg(long = "debug", env)]
    pub debug: bool,
 ```

Removed `debug` and `dap` features, now the code contains it by default and disables it if `debug` is `false` in the config.
The `Config` has two stages `unvalidated` and `validated`. The config can be validated by calling the `unvalidated::Config::validate` method.

Co-authored-by: Brandon Vrooman <brandon.vrooman@fuel.sh>

Co-authored-by: Brandon Vrooman <brandon.vrooman@fuel.sh>