Fix crash when store list is not provided

Previously, the SDK expected storeList to be set by integrators and would crash if only directDownloadList was provided.
This fix ensures the SDK only crashes when both storeList and directDownloadList are missing.

Merge pull request #51 from HeyPouya/refactor/improve-code-quality

There has been many various improvements in the codebase introduced with this commit such as:
* Extended modularity and modules
* Added unit tests covering more than 85% of the app's code
* Adaption of clean arch for future extendability
* Improved image quality of stores
* Made the api easier to be consumed for integrators
* Fixed many minor bugs

Update README.md

Upgraded the library version to 9.5.0

Upgraded library's version to 9.0.0

Updated README.md

Upgraded library version and reformatted via ktlint

Revert "commented group name in library"

This reverts commit 4c782d2.

Update README.md

upgraded all dependencies to the latest version - reduced images size