Use ID+Value beans instead of just Strings and fix some typos

[rocboronat]

As it's common to need the ID of a given value and not just its label, this PR use complex beans instead of plain Strings. Usually, you need to work with key+value beans, so just working with the label of an item doesn't help too much.

In this approach, we will always work with the id and the value, so the client code will be simpler.

In addition, this PR also fixes some typos: there are lots of "spiner" in the project. Whoops!

@MdFarhanRaja thanks for the project, BTW!