New: `row()` methods - operate on a single row.

- The rows() method allows operations on multiple rows with a single
  call, this new singualr option, `row()` performs operations on a
  single row, allowing fine grain control and easy access to certain
  aspects. For example. `rows().data()` will return an array of data
  objects, even if there is only one row as a result of the selector,
  while `row().data()` will return the data object directly.

- Impletemented thus far:

  - row()
  - row().node()
  - row().cells()
  - row().data() - get only as of yet
  - row().index()
  - row().remove()