[Refactor] Move data type match verification from LQLiquidPackage

Move data type matches from `LQLiquidPackage` to:

* `LQValue` and `LQVariable`

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>
[Reset] Soft and Hard reset improvements

Singleton is now "nilled" instead of its internal properties.

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>
[Tests] Kiwi structure + LQDataPoint unit tests

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>
[Tests] Add Liquid integration tests

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>
Code reorganization

`sharedInstanceWithToken:` reusing `sharedInstanceWithToken:development:`

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>
Liquid package is stored on a file per API Token

Each API Token now has its own Liquid Package file.

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>
An assert/error is raised if singleton is not initialized yet

Signed-off-by: Miguel M. Almeida <miguelcma@gmail.com>